While I tidying up some patch cables I got to thinking that I really have zero need for my old ST hub to still be mounted or wired. We still use SmatThings since we have all Samsung appliances and a couple TV's but that's totally separate from the hub.
I keep mine because it’s the only way I know to update SmartThings firmware on their contact sensors that I have. It has no connected devices, and I only used it for 4 days (after the Wink meltdown) before buying a Hubitat hub.
I have an electronics museum showcase in my office where mine will soon go to join other retired relics including a Motorola flip phone, BlackBerry, early gen Apple TV, iHome, and a Gen1 Hubitat (hub #3). I used to have more things in a bigger case but had to downsize recently when I moved west.
However, for now I still use it for Ring and Sonos integration onto my housepanel. I can’t seem to get the HE integration for these to work reliably. My old ring doorbells work fine but my new one refuses to show up. And Sonos keeps dropping and adding duplicates. Anyway the point of this post is my museum which gives me pleasure to see.
I was fortunate to sell mine when they were unobtanium last year - at a modest profit. Like the OP, I got to the point where items were in the app, but we're not connected via the hub.