Ok, yes if we are just talking about faces.
But when people say just take your own photos, I’m thinking of architecture, animals, landscape etc.
And again, I don’t paint photo realistic portraits, and I have weird tastes. Free image sites are not as useful if you are looking for weird outfits etc.
I do work from my own photos as much as possible and alot of my stuff is more amalgamation of elements but I just did a quick search of the site you linked for subjects I’ve looked up in the past and found no or few examples.