There are no real winners with the emerging status quo. An increasing number of men are frustrated because their dating prospects are poor if existent at all, a lot of women either become single mothers or have to bear the moral weight of having aborted their own child (and lack an actual loving partner even if they get laid from time to time), a lot of sexually active men and women contract lifelong STDs, and even those lucky few effboys live jaded lives without knowing the happiness of a meaningful, non-superficial relationship.
Because most people aren't winning the love game, I don't believe this is sustainable in the long run. Either there will be a neo-trad generation which rejects the aimlessness of the current one or technology will allow for more satisfying distractions that make single life tolerable for everyone. For example, robots or simulated romantic partners via AI and whatnot. If it boils down to the latter, then fewer and fewer people of either sex will be having live relationships or flings, making the whole "polyamory" thing a moot point.