Oh, I didn't know that. Still, since everyone seems to add everyone to all of the things in our workplace then, the effect is the same – just a bunch of noise and an endless turning off of notifications. I just logged in and again had 100+ notifications from groups I've never heard of before, nor subscribed to. My feed is full of stuff that's of no meaning to me, and so the whole thing becomes useless. Maybe it's useful elsewhere in other organizations, but I wouldn't know.
I honestly can't tell if you're being facetious; comparing Workplace to e-mail seems disingenuous, but I'll bite. E-mail, being a decentralized protocol, gives me – the consumer – control of how I shape the incoming feed of data. I can, and do, ignore any e-mails not directly addressed to me, either via the To: or Cc: headers. Anything else goes into a different folder, which sometimes I check for relevant details. Sometimes I'll notice what is essentially corporate spam, and so I make a rule to just delete those messages. I have a very clean inbox, and I've never missed an important piece of communication using these simple rules. Ultimately the only algorithm that controls my feed, is the one I design.
By contrast, the feed on Workplace has never been useful to me, since it's just noise. The only way for me to have it not be noisy, seems to be constantly tweaking subscriptions, or just ignore it entirely – the latter option has proven the most effective. Maybe it works for some people, but it doesn't work for me, nor my immediate colleagues who also gave up on using it for anything of consequence.