It's AI art out of characters neither of those devs own. If you're fine with that crying about plagiarizing and stealing is imo pointless. Neither of them are doing anything new in any way and as far as I know haven't claimed anything to the contrary. I agree with "I can do better than that" part though. This does feel like someone just got tired of CutePercentage milking the patrons for years before giving proper sex scenes with the main ladies and instead of waiting decided to do the same thing and just get to the point much quicker.
And imo that's how things should work. If someone doesn't deliver what they promise, their spot should be overtaken by someone who gives the customers what they are asking for. All that assuming that copyrights aren't a factor which they clearly aren't considering where we are.