This actually will hurt, because: "Firefox's revenue is subject to the overall trend of the search market and our product performance, versus a guaranteed payment." https://arstechnica.com/information-technology/2020/08/firef...

You are missing the point it’s not that you physically can’t do that but you can’t do that while supporting (as indirectly financially) Firefox, it also ensures that Firefox doesn’t go out of their way to push people to de-google.