Assalam o 'alaykum,
There has not been more exaggeration and excessiveness in this Ummah about any other personalities more than Sayyiduna 'Ali (may Allah be pleased with him) and Shaykh 'Abd al-Qadir Jaylani (may Allah have mercy on him). Rawafid went into extreme regarding Sayyiduna 'Ali and Ahl al-Bid'ah went into extreme regarding Shaykh Jaylani.
This was something also noticed by Mujaddid Alf al-Thani Shaykh Ahmad Sirhindi (may Allah have mercy on him). He writes in his Maktubat:
"A group of 'Abd al-Qadir's disciples had excessive reactions (ghullu) to him and in their love for him they went beyond acceptable limits. This is like the exaggerated lovers of Sayyiduna 'Ali [i.e. Rawafid]. Allah Almighty bless his face. From the words of this group [of 'Abd al-Qadir's exaggerating disciples], it is clear that they consider 'Abd al-Qadir to be more excellent than any other protégés of Allah, before or after his time. Other than the prophets it seems as if they give the greatest preference to 'Abd al-Qadir. This is from excessive love.
What if it said that more miracles appeared from 'Abd al-Qadir than anyone else, and therefore he should be given preference? We say that the number of miracles is no proof of preference. It can be said that a person who has performed no miracles is more preferable than one who has manifested miracles.
The shaykh of shaykh (Abu Hafs al-Suhrawardi in his 'Awarif al-Ma'arif, after mentioning the miracles of shaykhs, says, "All miracles are a gift of Allah almighty which manifest to some people through unveilings. They share these and [appear to be] superior to others [who do not have the same experiences.] They receive nothing [in terms of spiritual growth] from performing these miracles, which are for strengthening a person's certainty. One who is given certainty does not need miracles. Other than remembrance in the heart and in the Essence, there is no need for miracles."
Performing many miracles to demonstrate one's excellence is like trying to show the preference of Sayyiduna 'Ali over Sayyiduna Abu Bakr mentioning Sayyiduna 'Ali's many excellence and virtues." (Maktubat, 1:293 - Revealed Grace, p. 215-216)
Mujaddid compares the bid'atis with Rawafid.
Bida'tis were deceived by many miracles of Shaykh Jaylani. This led them to attribute the qualities of 'ilm al-ghayb, hadir nadir, etc. to him. Then they attributed false quotes to him and started to call him for fulfillment of their needs.
May Allah save us from this excessiveness.