Markets are exceptionally efficient over time, just like nature. Barring cataclysm, organisms that are displaced from their niches take ages to go extinct. It's the same with businesses. And what do you mean "immediate"? Days? Months? Years? Market effects take time, as anyone who has studied marketing will tell you.
> what would stop everyone who doesn't like that from switching browsers instead of upgrading?
The fact that they're human beings with their own lives and finite attention spans. There is an entire body of work segmenting markets into categories like innovators, early adopters, early majority, etc.
Did you wait in line for an iPhone on launch day? Why not?
> If there was a truly efficient market
https://en.wikipedia.org/wiki/No_true_Scotsman whats a truly efficient market?
> that speaks to a lack of a competitive environment
The environment is plenty competitive. There is no further proof required of this than the continued rise of new companies that displace their competition. In a thriving ecosystem there is lots of death as well as lots of birth.
> The market has failed
It hasn't, it just doesn't move on timescales you can relate to easily. Organizing people to make and distribute things takes unimaginable time and energy. Supposing that a centrally planned intervention can be more efficient is the height of communist fallacy. It has failed every time it has been tried.