Most text editors people use (like VSCode) generally automatically adjust tabs to be whatever the standard indent is for the project (and convert to spaces if it's necessary). As a result, indenting with tabs usually just works, and so most people just learn to do it that way. Also people are used to using tabs for indent from things like Word which they used before learning to write code. As a result, I've noticed most people use the tab key (even if their not technically "using tabs" every time they do it).