At least for humble store, they essentially sell steam keys. Which at least complicates that argument. So it is not really a different distribution channel and the product is available on steam for that price. Just not on the Steam store.

I get this but, for what I know (I might be wrong tho), steam doesn't get a cut from keys sold externally so they are technically selling them at better conditions elsewhere?

Steam have an effective monopoly here. Even if they have that because all the other platforms are shit. So the argument for just going to another store doesn't really help as that just causes a massive loss in the market share of who you can sell your game to. Plus if you consider the other requirements of if you sell on steam you cannot make your game cheaper via a different distribution method means that you have to eat that feeling and cannot pass it on to customers. Which does not give game Devs much power to negotiate for a lower fee at all.

I know that but that's not really steam's fault? I mean, epic offers lower fees, but they are shit so nobody wants to buy from them; however, that's not really steam's fault. You can't blame steam beacuse the competitors are objectively worse.

EA tried to have a launcher, but they are so bad at it that they've come back to steam. That's... EA's fault for sucking so bad, not steam fault for being more convenient.

And I say this fully understanding that they have a de-facto monopoly; but the reason is not because they have the only product, it's because the rest are much wose.