@DaBackpack Your thing about inevitable endings seems incredibly vague, so Im not responding to that in particular, but both of your examples from CLANNAD and Little Busters! overlook the same thing: the essential messages that were, in fact, some of the most important of the entire story which were conveyed as a result of the endings playing out in the way that they did.
I really recommend you go read @Karifean’s post about the meaning of LB’s ending, as its probably the best Ive seen it put yet.
CLANNAD’s ending is much more complicated because of the complexity of how the light orbs and the town and the Illusionary World actually work.
I dont think I could even remember it all without going through CLANNAD again, but every single character in the story not only teaches Tomoya something either about himself or about relationships/life, but also reveals to him something that, when you add it all up, the ending comes to not only make sense, but possibly even be, as you say, inevitable.