Firefox Quantum is the best Firefox ever and certainly not one precursor to the ultimate demise of Mozilla.
As always, everything has its drawbacks, and Firefox Quantum is no exception in that regard. However, the number of affected people is rather small compared to the whole user community.
off-topic - split from t=24979
off-topic - split from t=24979
Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:60.0) Gecko/20100101 Firefox/60.0