If you listen to the peanut gallery here you will never update anything again. These forums can be compared to a hospital in that only sick people come here with issues. Almost no one comes here to say everything is peachy keen and how much they love their devices. If you visited a town and went to the local hospital, found only sick people there, would you then assume that the entire town is sick.
As for the iPhone 13 there are no reports anywhere from established pundits, reviewers, tech experts, etc. that there are special problems with the iPhone 13 line and iOS 18. Whenever a new version is released, social media like Reddit fill up with complaints with just about every issue possible. A fews day later the complaints disappear as users find out their issue was due to user error, misunderstanding, or resolved by a simple restart of their device.
I use an iPhone 13 and installed iOS 18 the same day it was released. It’s now on iOS 18.0.1 and still running fine.