I've always added it to the project's gitignore because I want to make sure nobody else adds those to the project, either, out of ignorance. I'm mainly doing it out of kindness to them, because I am definitely removing them from git again and it's going to cause them some pain.

In the future, I think I might just be less nice about it. I dunno.

Yeap. To reduce pain, you need to work with reality rather than ideals. If you work with a big group, you either add a few lines into your gitignore, or you write code to check for those very same files in your CI/PR system, because you're tired of reversing commits and rejecting PRs because you're the only one that cares about a few extra files.

I’m not sure kindness is the best framing. At least, not in terms of being nice to any particular person who might commit unwanted files by mistake.

It’s one of several tools a project can use to ensure quality, alongside eg linters and formatters. Automating those (in this case by defaulting to the expected outcome) reduces friction on basically every operation anyone might do in a project, in any context.

Through the lens of kindness, it benefits you as well as your team… and ultimately everyone else downstream, since you’re all not wasting time and cognitive load on trivially preventable mistakes.