How about hosting an ADS-B receiver, tracking nearby air traffic. It doesn’t serve any practical purpose other than participating in the crowd sourced network that feeds sites like FlightAware and FlightRadar24 (and you get a free subscription by participating)

As with many others here- Wireguard and public IP. Add to that I can choose between split and full tunnel to either use the connected network for anything not on my network (split) or have everything routed through the network (full tunnel).

It works almost all the time. The times it doesn’t usually can be attributed to me not switching off my wireless mouse.