"Check out this alternative road vehicle I invented: it works on most surfaces except it can't drive on inter-city roads."

"You could fix that by builing a rail track and using a train."

And everyone you ever want to share files with locally also has access to your home VPN?

That's an even worse solution than the hacky workaround of just teathering my internet connection.

The whole point of these solutions is to not have to transmit data over the internet, it should work over a local dynamic connection.