Is Mastodon’s strictly chronological news feed based on a wrong assumption?

The assumption is that centrally managed social media is bad because their algorithm is bad. But actually, they are bad because they are centrally managed and force one algorithm onto you. I’m not even advocating algorithm-by-choice. Even instance-specific algorithms would already work and would make the whole experience much more enjoyable and less boring. And if an instance’s algorithm(s) is too aggressive, it gets defederated. That would result in a much more exciting experience imo. And by the way: what’s the problem with getting old posts back in the timeline if it makes the overall conversation more interesting?