Well, obviously I'm going to say my own demos.
https://cybereality.itch.io/decay-a-real-time-experience
https://cybereality.itch.io/ella-a-study-in-realism
The art for both the demos were purchased on https://www.cgtrader.com/ and I did not spend more than $100 each, the models are much cheaper than you might assume. And I would have never been able to create art of that quality myself, but for $100 I saved tons of times and got something way better than I ever could have made.
The people berating asset stores or asset flips aren't real developers and don't understand how game development works. Games are huge productions, AAA titles may have hundreds of people working on them, or even over 1,000 (if you include everyone from marketing, legal, the localizers, outsourced teams, etc.).
But even if you just look at the creative aspect, the artists, programmers, and designers, there are still whole teams doing it. Most people will just credit one dude for the whole game, like Cliffy B. But Cliffy didn't model the Cog 3D assets, someone else did. I would say the art and engine programmers had more to do with the success of Gears of War than the design (though it was a really good game). Would it have been still good if Cliffy B had to model all the art and do the music and voice acting himself... no.
Yes, you have a few wizard indie developers that can do everything, but they typically work forever, some of those big indie games took 4 or 5 years to create. I created Decay in 1 month, and made Ella in 2 weeks. That would not have been possible without buying art. And most of the problem isn't the assets themselves, it's that amateur developers buy stuff from the store and make crappy games. The problem is that the game is crappy. It would have been crappy with their own art, or even if they had the money to hire the best artist in the world, it would still have been crappy.
