I mean, when people are talking timeline with Lauri, I don't think its really that he's too old to play with the young guys. He's getting near the edge, he'd be early 30's but probably still have some good years left. Its more like, these guys will be ready to make some noise in 4-5 years. Until we hit that point though the way the system works, winning is counter-productive. Lauri kinda accelerates things so we might not get as good picks until then as we otherwise might have, or might make us start winning earlier than we'd expect, and so maybe this iteration of the Jazz rises while they are still a player or two short and stalls out as a first round playoff team again. Would suck to go through all of this and then have to restart before we ever even get anywhere.
If you keep him you keep him in the hope that you can fill in one of those players you need through other means so you don't have to go through the draft. Exchange some of that potential draft value for keeping the door open to build a good team through a homerun trade.
But yeah, George, older, more expensive, under contract almost as long, shuts the door on trading into a good team, but still a good enough player to threaten draft position is worse in every possible way for us. Wouldn't happen unless the 76ers were willing to give up way more than would be rational for them to do.