I only use lf in foot to have a preview of a file (image, text, pdf, ssl cert, everything with sixels, cat or the specific command) without opening or searching for that file first. It’s faster to just use lf to search for a file instead of opening every single one. Other than that I find using xdg-open, cp, mv, rm etc. is faster compared to using any file manager, probably because I never learnt lf’s shortcuts properly. All GUI file managers I know are bound to their DE, eg. dolphin and nautilus, which sucks with a WM.