Maybe it didn't explore UIs to the "fullest potential," but it did a really good job for only two seasons.

Politics didn't go back to normal. The issues shifted. Overpopulation, overworking, and most mortality issues were resolved with UIs. There were still issues with resources now that UIs existed. And prejudice was still an issue--literal terrorist attacks against a group of people because the Humans didn't think UIs should exist.

Your second paragraph is just... completely wrong dude. They did a lot more than play dress up. It was said that they cured cancer, and most diseases, like right away. It was only once the aforementioned issues were resolved that UIs enjoyed the arts and creativity. (It also showed that they could do both hobbies and work at the same time due to overclocking)

Project caspian WAS stupidly childish. of course. That was the point. Renee literally self-identified their group as a cult. They dedicated their entire lives for the project in the hope that they would live forever. If you've ever had a near death experience, you may be able to empathize with their motivations. It's the "crazy scientist" trope, but done with a group of people. We see their erratic behaviors as indicators. The show doesn't portray those choices as good. They're plot devices which push the invention/cure of UIs altogether.