I’m not convinced you need specific toilet bowl cleaner if you clean it regularly; a lot of them are really strong chemicals that are unnecessary, but it does depend on your situation and the water you’ve got etc. Loose stools may need more attention.

A bit of all purpose cleaner really is all you need imo. But a it hard water you’ll need to up it to something containing a (preferably buffered) acid to remove soap scum and hard water deposits.

Vinegar has its place but I find it almost universally disappointing when cleaning. In particular, it’s not got any surfactants or ability to bind to dirt or grease.