This is a good description I think. I sometimes keep that app on in the background, joining various shows to see what's happening. I like discovering new books, new sellers, and discovering how pokemon, mtg, and sportscard sellers work. I was always curious about mystery boxes, slabs, breaks, and all those random contests. I don't participate in them but I at least got to see them in-person. As a buyer, my paypal account gets charged right away so be aware of that. It's also difficult to find people who grade accurately (which is my experience from instagram). There are some dealers on Whatnot who grade well (in my experience) but it takes time to find them. I've also found myself buying something I don't need just because I've been watching the show for awhile and my discipline breaks down.
I find the app entertaining but I find conventions, my lcs, and this board to be the place where I can focus on being the kind of collector I want to be.