If only Chrome could do the same thing to Edge than people might be clamoring back for Firefox.
That said, Firefox would have the least ability to stop this... if it gets to all out mudslinging the only option that would be "safe" is Safari on MacOS using duckduckgo or something. As any other config someone can and would inject "nudges" to the other.
[1] https://www.zdnet.com/article/former-mozilla-exec-google-has...