the fee exists, at least from what I have gleaned historically, to provide some mild barrier to people who would otherwise spam the App Store with crap. By building a modest amount of hoops, it keeps the laziest spammers out. (Also something about "paying to keep the lights on", as if AAPL needs money these days)

In practice, well, just search this site for threads about it. I'm not sure, like you indicate, it's worthwhile for the browser ecosystem.