The tech update doesn't need any art outside of a few backgrounds needing to be expanded. The entire tech update is just allowing the game to support more resolutions and some code things to make testing for bugs quicker. That's it. The tech update doesn't need art.
Dark Cookie spends all his time drawing new backgrounds, new locations, redrawing characters, random objects that don't see any use in the game, he draws everything except more sex scenes for the next update. All the new art he draws just adds more work to the game. He makes up new locations and spends a week drawing the location so the coder has to implement a new location, the new location now needs more characters added, new quests of tl:dr text full of dumb memes, new braindead minigames etc, it just snowballs.
While the coder is sniffing glue trying to figure out how to make the resolutions fit on phones Dark Cookie is drawing location after location coming up with more and more characters no one asked for that will have 1 scene in the next 6 years. While the tech update is nowhere near completion and will probably never be completed, Dark Cookie has created this massive backlog of locations, characters and storylines to be coded in the game. Most of it probably never going to be in the game because the tech update will never come out. They're not even done with the pre-tech update in 2 years. The tech update hasn't even started and Dark Cookie is already drawing things that are 4 updates in the future.