Kingdom Hearts Was Riku's entire story arc hilariously avoidable?

So I've finally been playing this game again (first time Final Mix) and this struck me. What if Donald had just said "Sure mate, welcome aboard!" when Sora invited Riku to join in Traverse Town? There seems to be room for 4 in the gummi ship, Riku just proved his ability to dispatch Heartless with ease and he even held the freakin' Keyblade without it teleporting back to Sora. What more proof that this kid just might be incredibly useful do you need?

Maybe Riku left before hearing his answer, or maybe he would have refused because he couldn't stand playing second banana to Sora, but part of me likes to think that Riku owes his entire story arc to Donald Duck. At least he gave him and Maleficent something to bond over; the latter knows all about not being invited.

 

Maleficent was trying to prove to Riku that Sora had new friends and didn’t care about them anymore, if this could then be disproven I would make the argument that the rest of Riku’s arc would have gone super differently

However I’m not sure that just that would fit everything. Riku still jumped into the darkness without any hesitation and so putting his friendship issues aside, I think it would come up in their journey that Riku is relying or is showing signs of the darkness being inside him.

Maybe KH1’s direction would change, but you would then have the story in RE:Com be about the real Riku and Sora fighting over who to save Namine, with the organization trying to turn Riku to the dark on purpose, Riku having to overcome the darkness and the end result would end up being similar with Sora asleep and Riku trying to help wake him up

The only thing is though that if Riku were never taken over by Ansem he wouldn’t have his appearance in KH2. This is something that may just need like, a butterfly effect chart to see how much stuff would really be effected