the kids grew up. It would be weird having a bunch of people in their late 20s and mid 30s to pretend to be kids sitting around a table with a 57 year old and his friends who are in their 50s as well. Full House was meant for the late 80s and 90s it was not meant to continue for 25 years.
It ran its course back then, and the network decided to end it. There has been talk of doing a remake of Full House. Most of the original cast has shown interest in doing the remake.
People stopped watching.
Thanks for all the answers