Once Scotty’s actor died they gave up making Star Trek movies with the old geezers and then cast the new Star Trek movies with young actors who could really play those action roles.
The original Star Trek was an action adventure and once that actors became old (by the late 1980s) its was sad looking.
Unfortunately the three Star Wars prequels I,II and III sucked and they had a young cast.
Actually they stopped making original cast Trek movies long before any cast members died. And they didn’t even stop because they were old. It was part of the sequel process, all the spinoff shows were supposed to get movies, but by the time they’d done 4 non-TOS movies and the 4th spinoff show the audience had abandoned them. That’s what caused the reboot, the quest for a new audience.
“Wrath of Khan”
Best of all of them...