There is no emulator that can totally emulate an Android device?

Is it true that there is no Android emulator out there (as of May 2021) that can emulate an Android phone so that an app cannot detect it?

Of all the emulators out there (I saw a 15 best Android emulator list), they were not able to do it? The reason is it’d seem a bit strange why it is not possible to emulate such an environment totally, if a US$99 phone can do the job. (and that some developers may write the emulator with the original goal of: no code running in the emulator can tell it is an emulator).

I think probably the official Android developer emulator cannot do the job either (maybe intentionally) or else it would be recommended as the method on some forum.