

It determines the price. If you “self-publish” on a web shop or something with DRM free downloads, you have to price it the same as on Steam, otherwise Steam may delist you. So devs can’t get around the 30% fee by offering a discount on their store.
And… practically, if the storefronts are the same price, most will just buy on Steam.
There can be other complications related to scammers, but that’s not Valve’s fault. Supporting both also takes more dev effort.
Rimworld took this route, at least for some time. It started only self published via the Ludeon Store yet ended up mostly on Steam because that’s where all the attention and mods went. I have the game bought both places, oddly enough.



If the disruption is temporary, it’s bad.
High prices will massively incentivize expanding fossil fuel production, which is exactly what is happening worldwide.
But the oil wells in the Middle East haven’t gone away. That oil will still make it to the atmosphere, sooner or later, and we will end up with an expanded production capacity.
Additionally, war is a terrible emitter.
Your scenarios aren’t wrong, but thing is they are all just temporary symptoms. The oil crises would need to be sustained, indefinitely, to stop those reduced consumption patterns from rebounding.