what was Eromersive's original reason for abandoning this game? Was the new one (don't know its name, sorry) that popular? Was he listening to his then patrons, or did he just lost interest?
No reason given.
I think he did indeed partially burn out.
He had made the mistake before to say the game is coming out next weekend and failing to do that. The release at the beginning of 2022 had a lot of "ready by the weekend" moments when he found some extra stuff that needed adding of scene that needed reworking. This pissed people off and they requested those update percentages.
I think what happened at the beginning of the year was that on steroids. The art bar had reached 100% for a while but he had decided to add new stuff because it didn't fit well in the flow of the game. And I guess when he gave again and again the "next weekend" message he just quit when he couldn't reach it.
Also it is possible that he wanted to work on something else (the photo game) and felt too much pressure from people awaiting the DB release.