Samsung has their own version of every built-in app. Text messages for example, they have a much shittier version of "Messages" (no RCS support at least a few months ago). Their apps get set back to default randomly. Photos/Gallery, email, web browser, you name it.
They then have other junk installed. Their own app store, their own voice assistant, and other useless/niche apps.
You are blocked from uninstalling any of it.
It is the scourge of Android. "Android One" was an effort by Google to curb it, but I think only Motorola signed up (in addition to Google, obviously). OnePlus started on the premise of a clean/stock experience, but have started losing their way (rather rapidly). "Nothing" is a new manufacturer aiming for a stock experience. Asus seems to be doing stock.
If you ever consider moving away from Pixel I strongly recommend prioritizing a stock experience over _anything_ else. Crapware is maddening, full of bugs, and likely full of vulnerabilities.