They're mostly posts announcing new packages etc. but there seems to be more bioinformatics-y activity than, say, mastodon or bluesky. The posts definitely have a different tone than what OP decries.
Every single community you can think of has likely a great forum out there, easily readable and searchable, where discussions on single topics last _years_ and go in extreme informative depth, the kind of depth that no platform like HN/Lobsters/LinkedIn can ever dream of.
The closest surrogate we have are issue trackers (like GitHub) or mailing lists, but even those offer such a poor UX that I can't but wonder..
The difference to linkedin is that biostars has 'in-domain experts' only; the postdocs, the staff bioinformaticians, etc. those are not the people who will hire you. The people who will hire you are on linkedin.