Are all files on a Mac encrypted?

Might be a basic question, but my Windows laptop was stolen. This put me in a bit of panic as pretty much all my personal info was stored on it and I realized that if someone were to physical remove the internal ssd, they'd have access to just about everything. So, I replaced it with an M3 MBA and chose to encrypt the drive upon setup. So I might have just answered my own question, but...assuming it was locked, if someone were to gain physicall access to it, there's nothing they could really do, right??