Sync the whole hard drive

is syncthing able to sync the whole hard drive with all folders and millions of files? would that make sense? of is the tool more like for one folder with some files in it? any experience?

Most people use it for the latter, I think. Sine file ownership and advanced permissions aren’t synced, there may be limitations depending on what your whole hard drive contains.

only data like pictures, movies, word files, no programm or system files