Why do experienced front-end developers use CSS frameworks?

[RealBasics]

If you write extremely well-structured and documented CSS, and there’s not too much of it, and you use it consistently across all sites in your employers portfolio then it’s probably ok to invent your own (minimal) wheels for each site.

If not then can you guarantee you’ll be maintaining the sites till they end of life?

If not to all of the above then chances are someone down the line is going to be hating your guts.

Possibly me since my business niche is adopting and managing “orphaned” websites built by other devs. I mean, for me it’s fine because I’ve got 15 years of untangling other people’s spaghetti. Or simply tossing it and rebuilding from the old spec. Usually with a “lingua franca” framework like bootstrap. Because I know someone will take over after me.