A long while back, I used to think that term limits were a good idea. I then became less sure, because that means that people in the legislative body are perma-noobs. This is a problem because that means lobbyists know more about how things work in the capitol than the elected officials.
Also, since no seat is safe for very long, elected officials spend more time trying to get reelected instead of gitting gud at the procedural parts of their jobs and the parts that require domain-specific expertise (imagine intelligence committees or committees that deal with computer anything; you don't want a revolving door of novices who can do no better than to blindly trust the lobbyists who tell them things)