oh hey, let's have a thought experiment in this world with no IP rules
suppose I write a webnovel that I publish for free on the net, and I solicit donations. Kinda like what's happening today anyway.
Now suppose I'm not good at marketing, but this other guy is. He takes my webnovel, changes some names, and publishes it online under his name. He is good at social media and marketing, and so makes a killing from donations. I don't see a dime. People accuse me of plagiarism. I have no legal recourse.
Is this fair?
let's have another though experiment:
there are two programmers. first is very talented technically, but weak at negotiations, so he earns median pay. second is average technically, but very good at negotiations, and he earns much better.
is it fair?
life is not fair.
There are also unfair situations that can happen, equally as often, if IP does exist, and likewise, in those situations, those with more money, influence, or charisma will win out.
Also, the idea that that situation is unfair relies entirely on the idea that we own our ideas and have a right to secure (future, hypothetical) profit from them. So you're essentially begging the question.
You're also relying on a premise that, when drawn out, seems fundamentally absurd to me: that you should own not just the money you earn, but the rights to any money you might earn in the future, had someone not done something that caused unrelated others to never have paid you. If you extend that logic, any kind of competition is wrong!