Every good QB that becomes a free agent becomes the top paid QB ever, until the next year or two when someone else becomes the top paid QB ever.
This is completely true.
Except Lamar isn't a free agent he's under contract.
So in his case you're talking about the best QB contract of all time. And major draft compensation. I assume the way he gets tagged will dictate the compensation, as previously it seemed like he would end up causing Watsonesque compensation. Now there's rumors of the non exclusive tag, so 2 1st, vs 3 1sts and then some is a hefty difference.
Regardless everyone's concerns with Lamar is his style of play is very different from literally every other top QB, and that stacked with the contract + draft compensation makes this an unusually high risk move.
The guys capable of being league MVP taking us to a superbowl, and he's also capable of completely crippling this franchise for the next 6+ years.
At least with Carr the ceiling isn't as high as he will almost certainly have no chance of being an MVP candidate, but it's pretty high. But in his case the floor is much much higher than with Lamar. If Carr ends up a diasaster it won't even harm this franchise as much as drafting Zach did.
Regardless if we go with Lamar, I just hope we get an OC that will run the ball like freak and use Lamar's gifts sparingly so that we actually might be able to get elite play out of him for 6+ years