This is the real through line that Rogue Like Evolution shares with Yandere Simulator. Not the long development time, or being subsumed by scope creep. It is that both projects are total and complete spaghetti code. Now RLE being 2D doesn't have something as egregious as the 5,500 polygon toothbrush we can all point and laugh at, but the game runs at all of 41 FPS on my Ryzen 7 & RTX 3070Ti desktop (frequently hitches to around 20 FPS and drops frame all the time), so it's pretty evident that 'optimization' is an alien concept to both projects as well.
Why does everything take forever? Assuming that they are working in good faith, it just has to be a nightmare to do anything with this game. Any part of the spaghetti you poke has the potential to break dozens of other things for no rhyme or reason. Say you all have the structure already built to enable X sex scene and have implemented it for half the cast. So why does adding in the art assets to enable it for the next girl just break everything and take forever to fix? How come every bit of added content, even if it seemingly is a copy-paste job of already existing content, has to be a bespoke nightmare of conflicts and bugs?
Like imagine if someone read The Lord of the Rings, fell in love with it, and then they decided to author their own multi-book long fantasy epic. Now take that same person, give them a 4th grade reading comprehension (so that they actually missed most or all of the subtext of LOTR), and have them start working on it for almost a decade straight; and they never once stopped to take a creative writing course or seek advice from other authors or an editor. Also they're writing this all on an electro-mechanical typewriter, which then needs to be transcribed into a word processor, before being printed out in masse before being physically mailed for their subscribers. Just 9 years in a perpetual first draft fan-fiction hellscape.