I would advise against using the AI descriptions.
I doubt they're the sole issue behind slow sales since in general the title and pictures probably make the sale in your category but I do wonder if there is perhaps some algorithm penalty that is quietly imposed by not making your own description.
Who knows, the algorithm undoubtedly has secrets that we'll never be sure of. What we can be sure of is that the AI descriptions offer a buyer practically nothing and if I was writing such an algorithm I know I'd apply a penalty to listings that offer nothing in the description.