Maybe HN should tag the posts automatically and then present a personalized homepage with topics based on your usage history like upvotes,clickrates, time spent

Maybe HN should tag the posts automatically and then present a personalized homepage with topics based on your usage history like upvotes,clickrates, time spent reading the comment section and other engagement metrics? I realise building and maintaining such a recommendation engine is not cheap, but a funding model can surely be found with such a big audience e.g. ads between comments. Yeah... no.