Amazon's previous VP of Prime Gaming said they "tried everything" to disrupt Steam
(www.gamingonlinux.com)
Well, no, you found a bug in a poorly maintained game. You don't have to accept anything, but if the customer support for both of the affected companies won't help you fix it then the recourse is to get a refund.
But that is true regardless of whether the bug is on Steam, whatever EA is calling their authorization system these days or the game itself. It's not a problem with the concept of a game featuring its own login flow, it's a problem with the concept of not maintaining games properly. There are plenty of games in that same situation with no second launcher in them.