Scrolling through a "feed" is a self-reinforcing loop, and you're being "fed" the pieces of content with which the algorithm has determined you will engage.
You spend your time scrolling, occasionally flicking a reaction or typing a quick comment, feeling inferior because it's not your birthday, you didn't eat at Ruth's Chris last night, and your 2.5 beautiful children haven't won the gymnastics competition. Sometimes there will be a random, intrusive political rant tossed in just to get your blood moving.
It's a fast paced amalgam of pictures, videos, and gifs on a jumble of topics.
And those shoes you looked at on Zappos last week are hovering menacingly in the corner.
Let's contrast that with the experience you have in an online community.
You spend your time focused on finding an answer, posing a question, or In an active conversation. The content you're viewing is there because you subscribed to it, and found it useful enough to return to.
You slow down, read the discussion, and possibly add your own thoughts.
If you connected intentionally with other community members, you might see content or messages from them (regardless of whether you've recently interacted with them).
There are pictures, videos, and gifs, but they make sense in the context of the conversation (again, a conversation you decided to join).
And those shoes? They'll still be over there at Zappos when you're ready to buy them.