Agree to disagree on the case of AI. Art is a job like any other and people making it deserve to be paid. AI rip off the hard work of those people to make flavorless art. The Reddit thread seems pretty antagonistic towards artists by calling them bourgeois with delusions and shit. An image on the internet does not equal public domain and usable by everyone for free (including to feed AI), they are protected by copyright laws. If you don't have the means to buy original art, nothing stops you from putting placeholder art temporarily.
There are very affordable artists out there doing really cool things, so at this point IDK. Unfortunately, it's like everything else, if you don't have the means for something, you are not entitled to a way to have it for free because YOU don't have the money. Placeholder art and early access are there to feed your project and allow you to add unique art to it! If your project is cool people will finance it and help you. If you are open to it you can even learn how to draw and it's an infinite well of free art!