How it works is interesting in itself but it is not the reason why these 'algorithmic feeds' have gained the nefarious reputation they have. The real problem with this type of technology is the way it allows the proprietor of the service to present its users a tailored view of whatever content the service offers. The way this view is tailored depends on what the proprietors' aim is:

Twitter uses algorithmic feeds to present its users with an ideologically driven view of whatever is being discussed, this can easily be seen by reading the first comments on contentious issues where they nearly always push some 'progressive' comments to the front, even when those comments are clearly less popular with users than whatever other comments follow. Comments critical of 'progressive' issues often require one or more extra clicks to be made visible. Sometimes this leads to the first page being devoid of comments, requiring a click to access whatever comments are present where those comments are nearly invariably critical of the 'progressive' issue being discussed. This does not happen when there are positive comments on those 'progressive' issues since these are presented directly on the first page.

TikTok and Youtube also use algorithmic feeds to channel users but their algorithms seem to be tailored to keep users on the site/app for as long as possible.