I know I'm fighting a pointless and uphill battle against common usage, but the problem with this approach is that eventually someone's going to come along who is better than those guys. The Andrew Luck/Wayne Gretzky/Alex Rodriguez level prospects who truly do only come around once every 20 years or so.
And when that guy comes along, you're going to need a word that differentiates them from the "top 5 per decade, was always a consensus No. 1" tier.
And when we come up with that word, people are going to start clamoring for it to be used a little too loosely, and it's going to slowly become more overused until eventually it's being used for everyone and once again the words fall down the rabbithole into meaninglessness.
I generally hate presriptivism, but sports fans are on a speedrun to destroy every decent adjective they get their hands on. And every cycle gets a little faster to water down the words. "Elite" took all of the 2010s to get dragged down from "in the argument for the best" to "any good attribute." We've seemingly pulled generational down from "once in a generation" to "five every decade" just in the 2020s to date.