I think the GP meant to ask "what problem does this solve for end users?" It's hard to market to consumers if your primary differentiator is only useful to developers.
The reality is, if a developer can generate greater reach, it gives more options to the consumer. And so in that regard it does solve a problem for the end user - they have more software options to choose from. Perhaps there is more competition, which I think we can all probably agree is good for users.
My laptop is where I do all of my serious computing. I have no desire to run bash or vim or tmux on my phone.
But if the cost of doing so is that the apps have to be mediocre, is that really good?