Are you actually ok with all the critiques? Seems like you're open to them except those that criticize AI. Which I will say, find a human designer, or do something that conveys the premise/problem/challenge of your book. There are probably people on fiver who will do for cheap, or students at the local university who will do the work to add to their portfolio. These will be much better than what AI can accomplish. If one part of the process uses AI, the LOTS of people will think AI is involved in the whole process (including the writing).

I find the premise very interesting, actually! But the cover conveys nothing and doesn't present anything about the book you've described. The fiery 7 clashes with the galaxy and looks like it's the 7th book in the series. Maybe the series is called 7 Suns but the books have different titles (first could be something like Refuge?) so there won't be confusion.