The more web development I’ve done the more I’ve swung back to just writing CSS myself rather than depending on CSS frameworks; I’ve ended up seeing these less as ways to accelerate development for a team that is skilled at frontend, but instead as a way for people who don’t like styling or have little experience in frontend development/low design sense to style things reasonably. But I keep seeing frontend framework…
I think this is only partly correct. I am an experienced front-end dev who is very CSS-capable, but I enjoy using Bulma[0] as of late because its default styling is very close to what I want already. The default style works well enough for me because the projects that I work on (prototypes, experimental stuff) generally don't involve or need custom designs.
Edit: However, I work mostly alone... back when I was on a larger team working on different stuff, we'd usually use Bootstrap. In my experience most Bootstrap users don't even know how to use Bootstrap well though...
[0]: https://bulma.io