First off, I think that's a false equivalency, as patenting is about ideas (in a platonic sense), not about instances of ideas (which is what copyrighting is).

Secondly, we already have that in limited forms with trademarks and copyrights.

Thirdly, I think the concept of intellectual property is one of the most brilliant social innovations in the past 500 years, as it aligns incentives to innovate (why would I innovate if someone will just steal my work?).

>it aligns incentives to innovate (why would I innovate if someone will just steal my work?)

it was true 200 years ago. It stopped being true about 100+ years ago. Whether somebody innovates or not became unimportant, as a bunch of other people would still innovate the same thing. Just look at airplanes innovation back then - multiple people were doing it simultaneously, and the fact that Wright brothers got patent actually slowed down airplane innovation in US for couple of decades after that.

Let me see if I understand your argument correctly:

1. Before 1900, when someone came up with an idea, it was unlikely that someone else came up with that idea.

2. Because only one person had that idea, patenting protected their idea from being stolen.

3. After 1900, however, multiple people would have the same idea, but only one person could win.

4. Because only one person could win, it became a net loss to all the others, as they could no longer innovate.

4a. One example of this is the wright brothers.

Is that correct? If so:

1/2. I believe that people have been coming up with the same ideas simultaneously for a long time. Leibniz and Newton comes to mind, for example.

3/4. But would any of them have been able to get investments into their projects if they couldn't patent it and then reap the benefits?

You don't get penalized for thinking of the idea independently. You get penalized for creating an instance of that idea. I think it's an apt analogy.

You get penalized for undercutting someone else's work, because there's no good way to tell wether you truly had an independent idea, or whether you're just ripping them off. You can read and share ideas from a patent all you want, so it's very different from freedom of speech.