How does Satoshi's anonymity affect the trust of users and investors in the Bitcoin network? Can this anonymity be considered an asset or a drawback for the legitimacy of the cryptocurrency?
Knowing that Satoshi's wallet has not been assessed for a long time gives the confidence that he didn't create Bitcoin just to become rich. His anonymity also proves he wants the system to be truly decentralised. Trusting a system that runs smoothly without the identity of the creator is better because a known inventor can easily influence the product. So Satoshi's facelessness is an asset to Bitcoin.
Bitcoin is the valuable asset that it is today because it's creator Satoshi Nakamoto, decided to practice what he created Bitcoin to be, and that is a decentralized digital currency. His anonymity has proven that he wants Bitcoin holders to be in total control of their asset, no centralized authority or even him can claim ownership of Bitcoin or it's network.
Maybe you are right there, that his disappearance complements with Bitcoin but even if he chooses to stay afloat, I think there won't still be a major difference or change with BTC.
His anonymity has proven that he wants Bitcoin holders to be in total control of their asset
I think his anonymity has nothing to do with that. BTC is already known to be decentralized, so it is already understandable on how should people use it. The only thing is, that regulation and centralization invades us and there are now people who sides on them but I won't totally blame them. They won't also side there for nothing but they might also see something that interests them that they can't find on its counter part.
no centralized authority or even him can claim ownership of Bitcoin or it's network
As for centralized authority, yeah but for him? Maybe it is possible, since he is the ones who created it and there is no harm on it anyway, so why not?