Luke's story is clearly done. There might be some untold stories in there somewhere, but those would be best left to novels and animation. After the response to Solo they're not going to recast the character, so they can't go back, and there is nowhere to go with him moving forward.
Kirk's story ended with Generations. Obi-Wan's story ended with RotS. Batman's story ended with TDKR, James Bond's with No Time to Die, and Wolverine's with Logan. Hell, Sherlock Holmes' story ended with "The Final Problem," published in 1893.
And yet, somehow, all their stories go on.
If you don't want any more Luke Skywalker stories, that's cool; you do you. But if you don't think there's narrative and fiscal potential left in that fictional character, and that millions of casual fans/audiences wouldn't want to see more of him... that's solipsism and dogma, plain and simple.
As for recasting? It worked for Obi-Wan, and Donald Glover seems to still be in the mix. If Disney/the next Lucasfilm CEO/whichever executive decides that the time has come to recast Luke (assuming deepfakes/AI still aren't up to the task and widely accepted by then), they'll go for it.