As for reliability, there have been a few ".io" outages and I remember ".club" going down a few years ago but DNS makes complete TLD outages pretty rare.
I'd say the biggest reason to avoid certain TLDs is the human factor. Humans are used to typing ".com" or ".org" or ".net". I don't have any data to back that up though, so it probably isn't a satisfying answer!
[1] https://blog.nameshield.com/blog/2020/04/30/choosing-the-rig...