In 1930s Germany it was the Nazi party.
In 1930s Germany it was the Communist party. The Nazi party was a response to that, time to go learn your history.
Steam and GOG is 0-30% on a scale as well. MS, Sony and Nintendo is 30%+certification which can be up to $90k per game, used to also require the SDK in initial development.
With Steam and GoG they only take a cut if you sell directly through them. Steam and GOG provides you a store front at no cost, they also provide you if you're an indie a limited run of keys(I think it's 1k or 2k first to stop astroturfing)+$100? or $200? out of the initial first sales for approval. If you sell your game through your own website it's $0, or through any other site(Fanantical, Humble, GMG, etc), the only people who get a cut are those other storefronts which is ~5-20% you negotiate with them.
With Steam and GOG the more you sell, the less of a cut they take. Activations through a of a classed 2nd party key, also count as a sale. Epic's 12% only exists because they're offsetting the extra 18% by using their own money, the minute that their tactics dry up they'll start notching it up.
As well, these cuts are nothing compared to other regions or other digital platforms. To give an example, the VG type store fronts in asia can take upwards of 90%(i.e. DMM, Getchu, DLsite, etc). Their scaling is based on "how much" you sell it for. Then as you sell more copies, their cut decreases as low as 15%. So if you sell a VN for $2, they take 90% until you sell 5k copies then it becomes 30%. If you sell for $100(not uncommon with some of the big names), they take 20%
You failed history, and don't understand the difference of the "ism" between the two.
There's no such thing as a free lunch. -- Milton Friendman