I've been making a lot of use of DaisyDisk over the past year: https://daisydiskapp.com
TUI version is free, though there is a paid app if that’s your thing
Back in the days you would use cleanmymac for emptiying caches and what have you, and daisydisk to find big folders
They still update it, it works perfectly, no version 2.0 forced obsolescence. Just a nice, reliable tool.
And yes, codex is eating my disk, too. Ironically my solution is mostly codex - I have a task which goes around stomping on detritus.