> Is "registers" still a real thing or its just an illusion at this point? I am pretty sure there are "virtual" registers or micro instructions (something like that, I forgot the terminology)

https://en.wikipedia.org/wiki/Register_renaming ?

But yes, register count is still a thing. Why? If you run out of registers, operations 'spill out' into main memory. Read: L1 (data) cache. Which is fast, but not as fast as CPU registers. And probably uses a lot more transistors & power.

Of course there's limits to that due to # of opcode bits available (eg. 32 regs, 3-operand instruction -> 15 bits needed to encode source & target registers).