I would assume that the answer is that the incentives for competing that way are small and maintaining a browser is expensive? You would have to rely on donati

I would assume that the answer is that the incentives for competing that way are small and maintaining a browser is expensive? You would have to rely on donations. Which gives me an idea that probably already exists: a kickstarter/patreon alternative for recurring donations. Recurring donations won't start until there are enough for continuous funding of the project.