I get the impulse to be indignant. What TFB and BB accomplished, and then what TFB accomplished even further in Tampa, are uniquely special and unlikely to be eclipsed in our lifetime. Even if Mahomes wins, he's still less than 50% of the way to just catching Brady.
Media and fans are used to having conversations about "the GOAT" because Brady kept that conversation active for the back 15 years of his career. It's the inertia. Everyone is a slave to the moment.
The meta between Brady and Mahomes is not new. I count the following "rivalries" discussed seriously over the years.
Brady vs. Manning
Brady vs. Rodgers
Brady vs. Montana
No one seriously debates these now. Or, rather, no one who debates these is taken seriously. Time will tell if Mahomes can truly catch Brady. He is already more impressive than Manning or Rodgers, but he hasn't caught Montana's pedigree, yet alone Brady's.
If Mahomes wins eight SBs, all you can do is tip your hat. It could never ruin my enjoyment of the six TFB won with us, because it will never touch the memories I have of all those awesome and unparalleled times.