Okay. Why?
Here's where I disagree: no player is a franchise (except maybe Michael Jordan for the Bulls - but even then they've had the Thibs-Rose years since).
Here's where I SORT of agree: it would be pretty much a first to trade a franchise player who wasn't asking to be traded. Players like Drexler, Barkley, Kawhi, Anthony Davis et. al. had all asked to be traded. Maybe DeRozan is an example, but even then, he was traded for a better player.
Now, I'm pretty sure that if you found out we could trade Dame for Giannis or Doncic or someone like that you wouldn't say that it "ruined the franchise," even if you still disapproved because of Dame's all-round-great-dude-ness.