But you probably depend on over 500 open source libraries and tools, mostly ones you're not aware of. (Do you ever use a linux VM to run or just develop your stuff? Ever use git or curl etc? Did you know that tools and components in turn use other open-source libraries that you didn't pay for?) The main reason you use such things is so that you don't have to worry about this question.

That’s a fine perspective, but the whole point of law is to guarantee outcomes. The license could easily say “if you make more than $500M, you must pay me $1M”. Why is that not an acceptable solution here?

I find this whole conversation baffling. Licenses and contracts are not a replacement for being a decent person.