> a vague sense of unease with using a closed source shell/terminal combo. That's much harder to overcome than paying for a shell/terminal combo. Of course, getting reasonably compensated for open source work is an even trickier problem.

I actually see them compounding... either one alone isn't great, but combine them and you're left with a tool that can be rug-pulled out from under you at any time for any reason. OSS with some monetization gives you a fallback of maintaining it yourself, while commercial non-OSS with a perpetual license at least means you can keep using an old version as long as you can manage. Commercial subscription software is at best ephemeral, and not something I'd invest (time, money, transition effort, etc...) in without a strong fallback option, and even then the benefit offered has to be pretty impressive to overcome those switching costs.