I think you're correct, but certain libraries are so widespread enough that it's sensible. Especially S3, SQLite (as mentioned), Postgres and Redis usually offe

I think you're correct, but certain libraries are so widespread enough that it's sensible. Especially S3, SQLite (as mentioned), Postgres and Redis usually offer good abstractions. Other than that, time and crypto are two things I also wouldn't code myself, both are just too easy to mess up.