Will Pi-minners became a millionaire.?
It is most likely to the same case as the Hamster Kombat.
Just like Hamster Kombat there are so many users of Pi network because of it prolonged duration of mining around 35+ million persons and If you check the total USD Market vol of Pi is 430230$.
On some exchanges thethe Value of Pi coin is 42$. but the prices shown on certain exchanges are for IOUs that may not be transferable across exchanges.
Although it is better then nothing. you can do mining of this coin. But don't make higher expectations from it.
Because expectations always hurts.