Missing target dates does happen all the time. Maybe my company is a bit more cutthroat than others but the workload (and subsequent funding) doesn't last if that is a constant problem. So when my team communicates a date we usually come in under that - and we do that while working 40 hour weeks.
But my other point seems to have been missed which is that I don't view the folks downloading the EGS client as their primary customers. They made sure to have a differentiating feature for their primary clients (the reduced cut) while initially offering none for the consumers. They're getting better by adding standard features in, which is a definite improvement.
To use your web browser analogy - if a new web browser released today with not a single feature intended for the folks downloading it and didn't even have feature parity with any of the standard browsers - it would be rightly ridiculed.
Depending on the industry I can completely understand missing dates being harmful to revenue, I just don't think the impact for Epic missing features, even if they're industry standard like cloud saves or shopping carts, is that high. Your team does sound aggressive and efficient so that is cool. I wish our devs could do that, but alas our company is not primarily a technology company so our budgets are not as competitive as they should/could be.
Your point about developers being their primary clients instead of the consumers is true. I have no doubt that Epic is prioritizing catering to developers first and foremost because it seems to be their strategy. Get games, either through aggressive exclusive deals and/or lucrative splits, and then the consumers will come, everything else is secondary. This I get the anger over, but from a business standpoint, I can't really blame them. Microsoft did something similar when entering the console industry and basically threw money left and right to get a foothold in the market.
About the browsers, I should have clarified I was talking about the platform wars in the 00's when things like Chrome first launched or Firefox started becoming popular and what we now know as common features, would take a while to come to other platforms.