Technical excellence and commercial success have always seemed to be negatively correlated in software, whether it was Algol/Fortran, Pascal/C, Interlisp/C++, and endless other examples. After a forced computer update, this still seems to be true.
Good news for Mozilla, I suspect.
Opera is now miles ahead of Firefox in terms of Quality In Use, but miles behind in market share. Thunderbird is claimed as the latest, biggest, best thing for email clients, but it is actually amateur hour compared to Outlook (which is hanging on with established corporates).
Apple seems to be the bright exception, and has also provided a sensible market for frustrated open source coders, but I cannot bring myself to trust them with any of my IPR (generated or bought) because they are so predatory.