I think it's "inefficient use of RAM" that they're talking about. If Firefox should conceivably run in 8GB, but ends up trying to use 33GB (in your case), that

I think it's "inefficient use of RAM" that they're talking about. If Firefox should conceivably run in 8GB, but ends up trying to use 33GB (in your case), that would obviously be bad. Mozilla just targets efficiencies that include people with much, much less RAM than you for their baseline.