It's a sad thing to see that the dev doesn't seem to be on rails anymore. Between very long periods of silence and an obvious lack of work done for a long time despite an arguable success, it's clear to me that the dev isn't capable of handling the game anymore.
I believe this phenomenon would be called Dunning–Kruger effect . It's basically a psychological bias where one person can overestimate their talent which lead to an issue where upon gaining experience, the realization of how much there's yet to learn and do dawns on them. So self-perception changes its sign to "minus" and you get bad work practices which lead to inefficient/stressing work and burn outs.
It's very common in lewd games, where most new devs have no experience in game-making which often lead to horribly designed gameplay mechanics, over-ambitious goals, poor writing, lack of general creativity, improper work ethics (People don't know how to properly debug, design their workflow and such, which lead to increase dev times and more development difficulties).
It's one of the reasons that despite being an actual indie game dev, i choose to not (yet) dedicate time on a new lewd game since i know the implications of game-making (and i'm waiting for my other game to be fulfilled before starting a new one). Something many new naive devs forget and fall into when they see the success of a handful of lewd game.