New Firefox is too dumb for that – you actually have to open that link in a new tab before you can send it to some other Firefox instance (and then close that useless tab again).
You can also buy an Android phone with Edge pre-installed by default like a Microsoft Surface Duo.
Microsoft has been trying to co-opt Android since Windows Phone failed. And they are able to do so because Android is relatively open (certainly more open than any mainstream consumer operating system has ever been). For instance, Microsoft added support for running Android Apps on Windows 11 and they added the Amazon App store to Windows rather than the Google Play store. Done completely without any involvement from Google. That is unprecedented openness for a mainstream OS. That's not to say that Android is perfect in regards to openness but the iOS/Android walled garden false equivalence that gets pushed around here is baseless.
But to be honest, it's mostly the other way around: people live on phones, and when they have to interact with desktops, they pick the browser that integrates with their phones in the most seamless way. Which means, inevitably, the browser picked by their mobile-OS vendor, since there is little or no choice in that world.
The solution is not to turn into a little enforcer/fanboi for this or that corporation, but to crack open the mobile world (as well as Windows or any future platform) with the force of the State.