Some people were looking for less pozzed mod hosting sites than places like Nexus Mods. I came across this place:
I haven't gone through everything there but it does have, for example, "Hogwarts Legacy, Historically accurate 1800's Hogwarts," "WoW Wrath Classic Gender Icons," and FO4 Grounded Commonwealth.
If and when Starfield starts getting modded I am sure you can imagine what it will host.
SKSE is hosted on its own, you have no reason to get it from Nexus if you don't want to - just google it and use the first link instead of Nexus. The other mods that Nexus is such a massive hub for, I have no idea on other options for that though. There are a handful of like mod 'packs' out there now, that tailor Skyrim a certain way and host it themselves but then it becomes a bit more of a mess to sort if you want to continue to edit it.