Eliminating Accounts

Easy: One account per device and a cap on the number of devices per IP address. And you can't set up an account without an active email, active phone number, and possibly even an active google or apple account.

But secondaries make the player count look much higher than it really is and EA shareholders put a lot of stock in appearances. Because they don't know anything about gaming. So don't expect the problem to go away any time soon. Or ever.