What are the exact limitations of TS4 game engine?

I think the engine has its limitations but most of the limitations come from their desire for the game to work on any computer. Sadly they've cut back on so many things so that the game works for players with potato computers from like 2011 that take 30 minutes to boot up and overheat the second anything happens. From what I understand their decision to do that is responsible for a lot more of the issues than the engine.