Your claim is that you suffer a _40 to 60_% performance impact by using Firefox from Chrome? Would you like to try that again? I see egregious comments like this of Firefox every so often and I always have to wonder if the last time people making these remarks actually used Firefox was in the pre-Quantum era (assuming one charitable interpretation). To claim that its performance is equivalent to using Chrome on a CPU from 2013 is disingenuous at best.
Firefox is not just perceived as 'counter-cultural', its importance lies in the fact that not using Chrome and similar browsers is also a vote not to support a browser monoculture online.