Actually the opponents (extreme sufis) made takfeer of Ibn Abdul Wahhab.
Ibn Abdul Wahhab said in his letter to the people of Maghrib:
و لهذا قال غير واحد من العلماء يجب هدم القبب المبنية على القبور لأنها أسست على معصية الرسول صلى الله عليه وسلم .
فهذا هو الذي أوجب الاختلاف بيننا و بين الناس حتى آل بهم الأمر إلى أن كفرونا و قاتلونا و استحلوا دماءنا و أموالنا
More than one scholars said It is wajib to demolish the structures over the grave (like Ibn Hajr al Haytami ash-Shafiee the sufi etc) because they are made by going against the Messenger peace be upon him.
This is the thing which made dispute between us and people until they started calling us a Kaafir, fought us, made our blood and money halal. [تصحيح خطأ تاريخي حول الوهابية 1/171]
I don’t care you can quote his out of context Takfeer but this quote is epic.
b) Ibn Abdul Wahhab said:
وأما التكفير فأنا أكفر من عرف دين الرسول، ثم بعد ما عرفه سبه، ونهى الناس عنه، وعادى من فعله، فهذا هو الذي أكفر. وأكثر الأمة – ولله الحمد – ليسوا كذلك
“And as for takfīr, then It is for the one who knew the religion of the Messenger (i.e. Islam), and then after he came to know it, he abused it and stopped the people from it and showed enmity to the one who practiced upon it. He is the one did kufr. AND MOST OF THE FOLLOWERS OF THE PROPHET PEACE BE UPON HIM ARE NOT LIKE THAT, PRAISE TO BE ALLAH. [Al-Durar al-Saniyyah (1/73)]
c) He said:
“وأما الكذب والبهتان فقولهم إنا نكفر بالعموم ونوجب الهجرة إلينا على من قدر على إظهار دينه، فكل هذا من الكذب والبهتان الذي يصدون به الناس عن دين الله ورسوله، وإذا كنا لا نكفر من عبد الصنم الذي على عبد القادر والصنم الذي على أحمد البدوي وأمثالهم لأجل جهلهم، وعدم من ينبههم، فكيف نكفر من لم يشرك بالله إذا لم يهاجر إلينا أو لم يكفر ويقاتل” ا.
As for what they say of lies and fabrications about us, when they say that we label people as disbelievers in general terms, and we say that it is obligatory for anyone who is able to migrate to join us to do so, all of that is lies and fabrications by means of which they turn people away from the religion of Allah and His Messenger. As we do not regard as disbelievers those who worship the idol [i.e., the built-up tomb] on the grave of ‘Abd al-Qaadir, or the idol on the grave of Ahmad al-Badawi and the like, because of their ignorance and because there is no one to advise them, then how can we regard as a disbeliever the one who does not associate anything with Allah, just because he does not migrate to join us and does not regard others as disbelievers and fight them?! [ad-Durr as-Saniyyah p 66, Sharh Kashf ash-Shubhaat by Ibn Uthaymeen page 40, Islamqa]
d) He said, They (his opponents) say that I say:
إن الناس من ستمائة سنة ليسوا على شيء،
The people are not following anything from the last six hundred years.
And
إني أكفّر من توسل بالصالحين، وإني أكفّر البوصيري لقوله: يا أكرم الخلق، وإني أقول: لو أقدر على هدم قبة رسول الله صلى الله
عليه وسلم لهدمتها، ولو أقدر على الكعبة لأخذت ميزابها وجعلت لها ميزاباً من خشب، وإني أحرم زيارة قبر النبي صلى الله عليه وسلم،
I say kafir to the one who accepts tawassul of saliheen, I say kafir to al Buseri (author of al burdah) due to his saying “Ya akram al Khalq”, And i say that if I would have power to demolish the dome of the messenger of Allah peace be upon him I would do that… And I say it is haram to visit the grave of Prophet peace be upon him..
After quoting all the accusations, He said:
جوابي عن هذه المسائل، أن أقول: سبحانك هذا بهتان عظيم! وقبله من بهت محمداً صلى الله عليه وسلم أنه يسب عيسى بن مريم ويسب الصالحين، فتشابهت قلوبهم بافتراء الكذب وقول الزور.
I have answer to all these masail, Glorified be You (O Allah) these are the great slanders, before us the slanders were on Muhammad peace be upon him as well that He (peace be upon him) criticise Eesa ibn Maryam and the righteous..
[الكتاب: الرسائل الشخصية (مطبوع ضمن مؤلفات الشيخ محمد بن عبد الوهاب، الجزء السادس) 6/12
Hanbali The Najdi scholars declaring certain tribes unbelievers was not based on one or two issues. Rather, it was a declaration of unbelief based on the totality of their conditions and beliefs. Among the tribes were those who denied resurrection, deemed forbidden things permissible, and some claimed they were not obligated by the Shari’ah just as Al-Khidr was not obligated by the law of Musa. They believed in the beliefs of extremist “Itthadiyyah” Sufi shaykhs. In every tribe, there were those who claimed knowledge of the unseen, communicated with angels and jinn, and invoked them besides Allah, like the two shaykhs Taj and Shamsan.
This is not an exaggeration by the Najdi hanbalis in describing the general conditions as some contemporary writers have claimed. Rather, many Ash’aris shared in describing these conditions, such as Shaykh Al-Sanusi, Al-Bayjuri, and Al-Khalili. They mentioned that many of the Bedouin people were apostates due to their false beliefs. Sharh ‘Aqidah Ahl al-Tawhid al-Kubra (p. 37), and Hashiyat al-Bayjuri ‘ala Jawharat al-Tawhid (p. 78).
Indeed, the Ash’ari scholar Al-Khalili even went to extremes and added in his fatwas the obligation to fight them and take their women as captives if they persisted. Concerning the Arab tribes like Al-Sa’adnah, Banu ‘Atiyyah, and others from the Arabs of the Levant, Egypt, the Hijaz, and other desert Arabs, he said:
من استحلَّ حكمًا علم أمره وحرمته في دين نبينا محمد صلى الله عليه وسلم فهو كافر، وحيث نهوا ووعظوا مرارا حلّ قتلهم وقتالهم وأخذ أموالهم، ثم ينظر في حال نسائهم إن كن مؤمنات مكرَهات لا ذنب لهن فيعلَّمن الأحكام، وإن لم يكنّ كذلك حلّ سبيهنّ وبيعهنّ كالحربيات انتهى… هذا حكمهم مع كونهم كفّارا، وبه يعلم حلّ قتلهم مطلقًا والحالة هذه، ويثاب قاتلهم، وأجر المقاتل لهم كأجر المقاتل لأهل الحرب مع خلوص النية؛ لأنه مجاهد في سبيل الله
“Whoever deems permissible a ruling whose prohibition in the religion of our Prophet Muhammad (peace be upon him) is known, he is an unbeliever. When they have been repeatedly forbidden and admonished, it becomes permissible to kill them, fight them, and take their wealth. Then, look at the condition of their women: if they are believing women, coerced and without sin, they are to be taught the rulings. If not, it becomes permissible to take them as captives and sell them like women taken in war… This is their ruling given that they are unbelievers. From this, it is known that killing them is absolutely permissible in this state. Their killer is rewarded, and the fighter against them receives reward like the fighter against the people of war, provided the intention is pure, for he is a Mujahid in the path of Allah. And Allah knows best.” Fatawa al-Khalili (2/282).
The Hanafi scholar San’ullah, who preceded the Najdi hanbalis by a century, described the general conditions in the Arabian Peninsula, mentioning that they believed the saints (awliya’) themselves possessed the power to benefit and harm. Sayf Allah ‘ala man Kadhaba ‘ala Awliya’ Allah (p. 27).
Al-Shawkani also mentioned similar things, then said:
“This is among the clearest proofs indicating that their polytheism has reached a level above the polytheism of one who says, ‘He (Allah) is one of two or one of three.'” Nayl al-Awtar (4/95).
Kindly see the following link for full detail
https://salafcenter.org/9572/