Using the local network for the connection is a garbage plan because Wi-Fi coverage and availability is not consistent enough to become mainstream. I am aware of two practical solutions for this: instant hotspot (assuming the sharing app can temporarily reconfigure the wifi settings, and wifi encryption keys can be transferred with a QR code) or OnionShare (uses TOR to make a sharable link using any firewall/NAT configuration, share the link with a QR code).
We need a WiFi standard that isn’t fucking bullshit (has cryptographic identity), and that can be expanded to devices too.
Using the local network for the connection is a garbage plan because Wi-Fi coverage and availability is not consistent enough to become mainstream. I am aware of two practical solutions for this: instant hotspot (assuming the sharing app can temporarily reconfigure the wifi settings, and wifi encryption keys can be transferred with a QR code) or OnionShare (uses TOR to make a sharable link using any firewall/NAT configuration, share the link with a QR code).
You don’t need to use TCPIP with WiFi. It can be ad-hoc and some other protocol.