why does the khutbah during eid prayers are done after the prayers while in jumaah prayers are done before the prayer

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His Slave and Messenger.

Some scholars sought the wisdom behind the Khutbah (sermon) of the ʻEed prayer occurring after the prayer in contrast to the Friday Khutbah. Shaykh ʻAbd Ar-Rahmaan ibn Muhammad ibn Qaasim Al-ʻAasimi Al-Qahtaani Al-Hanbali An-Najdi wrote, “The wisdom is that the Friday Khutbah is one of the conditions for the validity of the prayer unlike the Khutbah of the ʻEed prayer. Also, the ʻEed prayer is Fardh (obligatory) and its Khutbah is Sunnah (voluntary); the Fardh is more important.” [Al-Ihkaam fi Sharh Usool Al-Ahkaam]

For more benefit, please refer to Fatwa 92716.

Allaah Knows best.