Some also check for other signals indicating root - for example, if Samsung Knox shows up as enabled in the build properties, but accessing it fails with an exception, the phone was rooted at least once (even if you re-flash an official firmware and re-lock the bootloader, the Knox Secure Enclave stays dead).

Tricking out these detections is a nightmare.

Yeah, Samsung is pretty bad (or good, depending on your point of view) when it comes to this stuff. I would never root a Samsung phone because of this mess.

The problem is you're effectively stuck with either Google or Samsung if you want decent performance, update availability, spare part support and the security of not having Chinese spyware embedded on order of the Chinese dictatorship. And Google is known for delivering absolute lemons as hardware, with next to zero support to make stuff worse.

KBC and Itsme are hard to trick into working with a rooted phone. I tried and dropped the ball at some point.