I can see another actor having a stab at Data and providing a slightly different take on him, but Dorn and Stewart have very distinctive presences and with the possible exception of Geordi the other characters are, frankly, kind of generic. So we have a show where the distinctive characters are distinctive because of the performances of the actors and generally not in a way that lends itself to imitation or reinterpretation. I'd also question the wisdom of recasting and rebooting something that became - and for all I know still is - the most successful syndicated TV show in history. It would no doubt produce a lot of nostalgic discussions about how Picard (TV Picard) was the bomb and how Stewart was the only man for the job. Jean-Luc would have been a very different character without Stewart, who invested him with a dignity and forbearance that at times seemed almost superhuman.