@hypolite
Your arguments fit a fediverse- or instance-wide algorithm. That sort of general timeline control I wouldn't want, too, partly because of the implications on the content creators' side you mentioned.
But what about an individually customizable ranking for postings that every user may prioritize differently for the personal timeline? Some will use it, others won't, some will just prioritize keywords, others may combine group membership with keywords, prefer original postings over shared, whatever comes to mind and suits one's needs … If every user chooses its own combination of parameters, there's nothing to intentionally optimize for on the writer's side.