I'm using 3+ year old hardware that was mid-range even when it was new and it seems to do everything I would want with reasonable performance.
If you are a (the) leading browser like Firefox once was, the "what are the complaints?" is the right question.
If you are a minor browser like Firefox currently is (~2.5% market share), the "what is it doing better?" is the correct question.
The people still complaining about firefox are its most faithful users. The reason some are vicious is because they are trapped - they'll consider cutting their use of the internet before using an non-FOSS browser. 90% of firefox's users left. People who could stand a closed browser have already decided to use one. You're in an extreme minority if you even know anything about firefox to complain about. This year the Linux desktop, of all impossible things, has become more popular than firefox.
Yet there's still this confidence and attitude about even the remaining users that comes from being spoon-fed cash by your direct competitor in return for nothing.
According to statcounter's stats, Firefox never cracked 1% of monthly mobile traffic any month from when stats started in 2009. Even Opera and UC have more than double Firefox's average for the last year and they are just Chromium forks users are downloading off the stores.
Additionally, my perception (from posts and discussions like these, I'm not a financial analyst and I have no meaningful insights into their business) is also that they probably receive enough funding through non-advertising means that they don't actually need to do this if they were to pare back the nonsense spending they're so greatly known for.
Last time I checked, Mozilla received 90%+ of its funding from Google. This is a situation that nobody likes (except Google, of course). These ads are an attempt to diversify income streams.
People are really unhappy that Mozilla gets money from Google, but also extremely vocally unhappy whenever Mozilla attempts to find other sources.
I haven't seen anyone suggest alternate solutions yet.
- full uBlock support
- the ability to still be themed
- first-party isolation
The common wisdom is that overall Firefox can feel bottlenecked at render and draw times (“less snappy”). That could be a result of a slower JavaScript engine (takes longer to get to drawing), or a result of poorer hardware acceleration (slower drawing), or a less optimized multiprocessing/multithreading model (more resource contention when drawing).
I honestly can't see it in the real world, but synthetic benchmark are pretty clear on that front.
I have at home 13 year old hardware running Firefox and no performance complaints.