> I'm not sure this is true for oil. For example, long standing sanctions against Iran prevented them from selling a lot of their oil and crippled their economy quite a lot (decreasing their income).
You're referring to international sanctions (i.e. acting with market power), not something anyone can do at the individual level. Not even the US could do it on their own -- if the US put sanctions on Iran by itself, Iran would just sell to Europe or Asia and not care. The only way it works is if nearly everyone agrees not to buy from them.
But the reason countries don't like sanctions on oil exporting countries isn't that they're ineffective, it's that they raise oil prices.
> Oil would come from other countries, they could increase their output while Saudis are under sanctions.
Yes it would, that's normal for a commodity market. When you remove a supplier, the price increases, which attracts new suppliers who may have higher production costs.
But the relevant part of that dynamic is that the price increases. The problem isn't that oil becomes unavailable, it's that your consumers have to pay more for it and the money goes to other countries you don't really want to enrich.
And if you have an international coalition willing to suffer higher oil prices then the much better alternative is a carbon tax, because then you get the money from the higher prices instead of Russia and OPEC, and can use it for things like subsidizing renewable energy or electric cars to mitigate the cost to your consumers and reduce the length of time you have to pay it.