I have a few things. If I have invested hundreds of dollars into purchasing a domain, I will likely renew it until I'm dead.
For handregs and cheap acquisitions, I do consider things like traffic. I don't understand why a domain I registered on a whim last month has 50 visitors according to SEDO...can these all be bots? Ahrefs shows no backlinks and there's nothing in the internet archive so whats up with that? Either way, I am more likely to renew the handreg that gets 50 visitors a month over a similar one that has 2 visitors.
Zeitgeist (the spirit of the times). Crypto and AI are two buzzwords right now so domains I have in this area or that might possibly be used in this area will definitely get a renewal from me if I feel good about them and especially if they have uses beyond those two buzzwords (or other buzzwords).
Offers. If someone has lowballed me on a domain or if I've received multiple offers on a domain, to me that validates my belief in the name and I'm more likely to renew something for at least 2-3 years if someone has expressed interest.
Companion names/Dream projects. I have some niche names that coincide with businesses/projects I am already running or fantasizing about having created. So as my online retail business continues to grow, for instance, some of the companion domain names I am acquiring could be useful later on or perhaps to a future owner should I end up cashing out.
Edit: More criteria - time is money and domaining for me has not been a self-sustaining business yet (I buy and renew more than I sell). My time is becoming more and more valuable each month and although domaining is a hobby, I have many hobbies and interests as well as a wife. All of these things need my attention. So if I renew 20 domains that fit criteria of new domains I bid on, then the $200 I spend on renewals saves me however many hours it might take to bid/handreg/research 20 new names. For example: why would I let rowboat.org expire only to search for and acquire sailboat.org or tugboat.org? I don't own any boat names but hopefully you get the idea.