What? This is simply not true. If anything, 30% is the standard for app distribution. Steam, GOG, MS Store, Playstation, Xbox, Nintendo, Apple App Store & Google Play are all at 30%. If it's a lot or not is opinion.
>Amazon's Twitch takes 50% fee
Twitch is not an app store, it makes no difference to this discussion. It just happens to be higher than 30, so you mentioned it. For example patreon takes 8-12%, but that does not matter either.
>Also Tencent, who is behind Epic Games lawsuit
Tencent is not behind the Epic Games lawsuit.
Please see preliminary hearing video where judge rejected such arguments like yours. Epic lawyers failed very badly.
So if the people would convince the politicians that loot boxes, game exclusives, wall gardens, tracking etc is bad they can force the big giants to stop it and no fanboy or judge in Texas could affect what EU m Australia or other countries would decide.