So it's been what now, 8 years since Apple has not managed to actually make this feature work?
"Right size all columns individually" option is there, when you click between the two columns in Finder in column view, but it is not persistent and essentially works for the single column only. Basically, it works exactly the same way if you simply double click on that border. Completely useless in other words.
Finder - most essential and probably most used App in macOS has the very basic feature broken for what feels like forever.