I register my side project domain names on Namecheap now... partly because they have a marketplace for selling the domain when I decide to scratch the launch.

(Most recent example: I made an unreleased browser extension for HN, the MVP feature of which is to let you block annoying users, such that any of their comments are replaced with poop emoji. But since I can't put an AI spin on that, to attract funding or job offers, I'm better off selling the domain names, and not spending any more time on it.)