If Mahomes wins, there's a big silver lining for Brady stans. There's always going to be a guy playing who is "the best ever but not most accomplished ever." That's the nature of sports...over time, it's like evolution, and the stats get more efficient, the QBs play more games, throw more passes, etc. This happened to Montana after he retired (Young was GOAT 1A, then Manning was GOAT 1A for awhile.) It happened as Brady was playing with Rodgers.
So that's inevitable. Sports discussion isn't interesting when there's no debate.
I like Mahomes better than Manning and Rodgers, and with a second SB, he's probably going to surpass Rodgers already on the GOAT list and getting ready to surpass Manning. If you want Brady to remain on the pedestal, I don't think there's any reason to worry about Mahomes until/ unless he reaches 4 SB wins because then, yes, he's really in the conversation. Sure, sports talk will call him the GOAT right now or compare the two, but that's just prisoner of the moment stuff. Aaron Rodgers? Who is that? Steve Young? Yeah, they're not shiny and exciting anymore. All that hot air for years about Rodgers just dissipated in an instant when Mahomes became the new prototype.