But then we might be ruling out a whole host of products, because of the incentive problems. No
one person has the incentive to fund the entire development of the software, since it's prohibitively expensive. But if offered at a much lower charge, they
would use it.
I mean, would you fund the development of MacOS / Windows by yourself, just so you can use it? (Keep in mind that person #2 can then free-ride on your funding and buy it practically at cost, since why not?).
Or let's take the argument to books. I assume most people wouldn't fund someone's salary for a year to write a book. But I really enjoy the end result of the fact that someone can write a book, then spread their costs on thousands of people. (I'm not too worried about the JK Rowling's of the world, btw, I'm worried about a mid-level author, not someone who is rich in our world, someone who manages to make a decent living off of a back-catalogue of dozens of stories and books. They're the ones who are usually the most hurt). You can of course extend this argument to things that cost a lot more to produce - movies, music, etc. Many things we value would not have been produced, simply because of lack of incentives (or lack of time while these people do some other job to earn money).
You can certainly think of alternative methods of funding these things, but they have their own problem. E.g. something like Patreon, which in some ways is a homage to how things were funded before modern capitalism - a rich patron would fund specific artists to produce great works.
And that's great! I love Patreon, and support numerous very deserving creators on there. But this has problems too - for one, some things are too expensive to do this way (e.g. most movies). For another, patronage gives a huge preference to things people know will work (how many people will fund drug-research to the tune of billions, with a small chance of success?). And patronage gives a preference to things people knowingly prefer - and again, we miss out on the mid-level artists of today scraping by, who can't get a large enough following, but still get some fans (and who potentially turn out to later be considered geniuses).
I'm not saying IP is perfect, and I certainly don't agree with all the things done for it (like the numerous extensions to IP which might not make sense). And our current system has issues too! We "missed" artists like Van Gogh, after all. I'm just saying that taking an un-nuanced view at this and concluding "IP is terrible, let's just get rid of it" is, in my mind, incredibly wrongheaded, at least if you believe that it won't significantly change the amount of stuff produced for the worse. You might have reasons to prefer that anyway, I suppose, but let's first understand the actual effects of throwing out IP law.