Google might at some point maintain two completely different Chromes targeting iOS, but I doubt anyone else will (including Firefox). Even with Chrome, I wouldn't bet on it. It's a very difficult technical problem with no clear, easily-marketable benefit to most people.
Apple knew what they were doing, they've "complied", but in a way where nobody would bother.
It's not like iOS users care anyway, or they wouldn't use iOS in the first place.