Well actually I don't know that Lamar is in the league of those guys yet, since they did it for longer than Lamar did.
As for the $, smart people care. Smart people don't want to win one and then suck for the next several years, like the Rams are and will continue to do.
Other teams have the same struggles. Bills didn't advance in the playoffs because beyond Diggs, they have literally nothing. Just a bunch of JAGs up and down their offense. And it showed.
When Mahomes got expensive, they shipped off Tyreek and gave him a hodge-podge of incredibly pedestrian NFL WRs and Kelce. Doesn't seem to matter there either, because Mahomes is the MJ comp, not Lamar.
When Aaron Rodgers got expensive, they shipped off Adams and gave him a ton of rookies and Alan Lazard. And it showed.
Think you need to take a look around the league and see what's really going on. The teams "loaded with weapons" are the 49ers, Eagles and Bengals over the world, who aren't paying their QBs dick.