Is that somewhat biased? - I assume the number of people using Firefox has a quite big overlap with people using ad&tracking blockers, which block many statistic sites. (Website operators may log user agent which will be somewhat accurate still)
This is always something I question whenever the analytics numbers come out. I know my adblocker blocks GA, so I'm not going to be included in any GA statistics.
Every time I've asked a marketing person about this they get hand-wavy about "it all comes out in the wash". But meanwhile they say things like "our analytics show that our market is mostly older and non-tech-savvy people". I'm not sure that the analytics numbers do actually show that. I think that's just the demographic that you can see.
