I'm not sure that's the case.. Right now I'm polling the MakerAPI every few seconds.. and because the /devices/all endpoint is so slow - I have to fetch each device individually.. so, for 100 devices that's 100 API calls every few seconds while the app is running in the foreground.
A websocket is a persistent (keep-alive) connection to your local Hub. If the connection is closed for some reason (ie: walk into an elevator) - it'll reconnect. It should be a lot less overhead than polling.
As for Hubitat's cloud expenses, I'm sure they're not free. But, ultimately they just need to direct traffic to your local hub. There's no server in the middle to maintain AFAIK.
