I 100% recommend that you avoid AI-generated assets in your game. The stigma around AI-generated assets is very real, and not going away soon. Although people might enjoy using AI for their own purposes, by and large they don't want to be subjected to other people's use of it. Moreover, while I don't have the data to back this up, I would have to think that among the segment of the population that plays indie games, the stigma around generative AI is even greater.

In the second part of the question you asked if you should just learn all of the skills...buddy, does that question not answer itself? Of course you should learn all of the skills. Obviously that's much easier said than done, but TBH I think the quality bar to producing something viable is not super high, so as long as you're not a perfectionist, you can probably do it.

Since I could be labeled as an "AI hater" based on those comments, I want to be clear that I'm saying all this to keep you from falling into a trap and not to further my own agenda. The generative AI route is not a magic shortcut to success, although it is being aggressively marketed as such. The shortcut only seems to lead to success if you ignore the fact that people don't want to be subjected to other people's AI content.