I feel this would be more useful as a utility to manage your MAC addresses.

That would let you, for example, clone a MAC address or IP address between your computer and a phone, and maybe automatically resolve contention.

That way, you can split purchased WiFi (such as on a plane) between multiple devices.

That way, you can split purchased WiFi (such as on a plane) between multiple devices.

You need a router for that, which fortunately is built in to most phones and computers these days.

That’s only going to work on one device at a time. Don’t think that your phone and laptop with identically MAC addresses are going to magically share the connection.