What monopoly? There is a monopoly today; it's called Steam. It has an immense userbase and plenty of user loyalty; it's not going anywhere. If Epic succeeds, there will be two major stores rather than one.
Are you a pc gamer? Because if you are, I don't understand how you can't see Steam as a massive monopoly.
Perhaps you don't because they have done almost all GOOD with their monopoly power. Offline mode, library sharing, massive sales, etc.. but they are quite a monopoly.
If 99% of my library is on Steam, why should I bother buying somewhere else? It's just an inconvenience to me. Ok I can buy off GOG and have no DRM.... how does that really help me? I can already play it on steam with no problems, my friends can play the shared game on steam, I don't have to worry about multiple platforms etc..
Anyway- steam is a massive monopoly and we are lucky they use their powers for good!
Network effects make Steam a practical monopoly. And it's probably no coincidence it has lower rates for AAA studios since Epic has gained a foothold in the market.
Steam has plenty of money and users. It also had little serious competition before Epic. While I'm a fan of well regulated markets, I don't think punishing Epic would benefit anyone except Steam shareholders.
Except gamers do not care about Steam being a monopoly (they are just a distributor and does not set prices), but would really be hurt if Epic and exclusivity of titles starts to take hold.