In the EU, it's complicated.

There is a very clear law that forbids any additional contract terms post the point of sale, so that if you go to a store, purchase a box with software in it and then go home to install it, when it pops up a dialog for you to "agree" on, you can just ignore it, nothing in that is enforceable at all. And no, small print text on the box that says you have to agree to terms in the software does not change anything. But that's not how software is sold anymore.

EULAs in general are not unenforceable, so long as they are presented before the sale. This is precisely why Steam (for example) now gives you the EULA before it lets you buy anything.

I'm not even sure you can generalize to "in the EU" here. A lot of contract law might be different between countries.

So for example, in Germany, an EULA would be considered an AGB, and subject to §303 BGB and following paragraphs, which e.g. means, "surprising" clauses which you cannot reasonably expect beforehand being part of the EULA would be unenforcable or §307 BGB would make certain kinds of one-sided/lop-sided clauses unenforcable.

Other EU countries might have other laws. I'm not really sure this is an area of unification, and a lot of the commonalities there is might be more due to the common heritage of Napoleon's Code Civil which underlies contract law in many european countries, instead of EU unification efforts.

There’s still some principles that it must be proportionate and reasonably intelligible to the average person. A 100-page EULA for end-user software generally won’t be enforceable.

they are generally thought to be, but require litigation- which is a problem for the general population!

corporations have enough money to tie you up in court with lawyers.

People always say this, but are there any real examples of corporations extracting damages from EULA violations?

It was a lot more plausible when it is likely the judge has never clicked past an EULA. Today unless you've dug up some archaic fossil the judge is perfectly familiar with this nonsense so you're in a position where the person who decides what the law is knows EULAs are bullshit nobody reads.

I'd expect a situation like Somerset v Stewart. Mansfield clearly didn't want to rule you can't have slavery because that's going to be extremely disruptive to powerful people - so he suggests they settle and then the case goes away and he isn't called to say anything. But Stewart refuses to settle, apparently nobody could convince him that it's in his best interest - so, OK says Mansfield: fiat justitia, ruat cælum (Justice be done though the heavens fall). Somerset walks free.

Are corporations relying on EULAs smart enough to take the L? I guess we'd see.