personally to me, star trek feels different since the jj reboot movies. honestly I'm kind of surprised star wars didn't get split up since that absolutely has felt very different in like classic vs prequel era vs disney era
I'm the kind of person who likes to find ways to split data tho
Things evolve over time. The original Star Trek from the 60s feels very different from season 3 of TNG, which feels very different from season 6 of Deep Space Nine, which feels very different from Enterprise, which feels different from discovery, etc, but they're all still the same franchise with the same themes at heart. If you want to split them the only fair way is to split every show into its own category, and even then shows like TNG, Enterprise, and Discovery evolve quite a bit over the seasons.
Star Wars though I'll grant you, the post-disney stuff is a mess (I maintain that the Last Jedi was a good movie and shouldn't have been ignored when they were making Rise of Skywalker though).