there's also marketing tactics of startup social networks (including LinkedIn at one point) where they try and email all of your contacts to get them to join..
there may be is a case to use legislation against this, but it will vary between countries and there would need to be proof found that GAFAM are colluding to only share links amongst themselves (YT links on Facebook groups seem to get through) and its not local moderators leaving default setting active..
@vfrmedia @msh @VictorVenema and there's Instagram simply not supporting any link, giving us the cursed "link in bio" thing.
I think there's definitely a certain hostility toward hypertext in their algos, and I suspect there is valid concerns for spam & malware, meeting their own interests in keeping people on their app.
Spam is actually the argument used by Pixelfed for copying the anti-link approach of Instagram. And I was just thinking the other day... spam really does ruin a lot of things