The immediate push to rely on an external library every single step of the way is quite boring! So much of it is outdated and redundant, by people who don't even know the standards have changed and that library is quite unnecessary now (except maybe for very niche cases).

There's this allergic reaction to using your own tools, which I find strange. Yes, I get it, don't reinvent the wheel. However, we're not reinventing the wheel! We're using standards that exist and provide what the libraries do.

Gluing together libraries and dealing with dependencies. There are few well written libraries that just work, like axios. Especially in React Native, looking for a library is like looking for scrap part in a flea market or in a junk yard.

Figuring out which CSS rules are actually used. I could swear I saw a tool 10 years ago that would go through pages and list unused CSS rules. Maybe it got too complex with pre-processors and CSS having its own macro language.

There are several.

I use a combination of (from npm): cleancss, PurgeCSS, UnCSS, purifyccs.

This is a solved problem with tailwind/unocss JIT.

framework/lib of the week ( fullstack dev )

Make things work well in Firefox and Safari, the new IEs.