not in this universe they aren't - many popular applications indent 4 spaces by default when pressing the Tab key, and render physical tabs as four spaces, for example github ;)
tabs of 8 space width are a legacy travesty that wastes space :)
https://www.kernel.org/doc/html/latest/_sources/process/codi...
https://wiki.musl-libc.org/coding-style.html
https://www.freebsd.org/cgi/man.cgi?query=style&sektion=9
https://man.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man9...