We expect everything on the web, including our user agent, to be free as in no cost. The only way to pay for the development cost is to sell to third parties aka advertisers. If people actually paid money to develop more advanced user agents there would be a market for them.
Why do people prefer free over paid? I think people underestimate the influence of advertisers and underestimate the value of their own time spent researching and dealing with crappy products. It’s almost like a psychological bias.
I like the idea of a better user agent but would I pay for one? Judging by my refusal to pay for quality journalism I’m guessing it’d be a hard sell. That’s another thing I should be willing to pay for but don’t for some weird reason.