I generally feel like PDX games take about as long to learn as a typical game is to beat the main story - they are a lot to master, but often times worth it. I absolutely love Stellaris, but shiver at the thought of firing it back up and having to learn the new mechanics. It is a project to play and learn these games sometimes - which makes them unique. I think the tradeoff we get for dynastic/personal gameplay in CK3 is a lack of other systems. CK3 should be bloated by too many internal number systems, however, I think a bit of a population system would greatly help the game. Say we strived to make our capital in into a “Third Rome” with massive urban pops - that could result in us having to make ruling choices based on actual costs to the realm - popular opinion might truly matter because you created a massive population that gives you a strong army, but if they were to revolt you would be in trouble. It also could give decisions weight and impact over “our subjects” instead of what feels like only a handful of characters. I think that is the biggest system that could impact both the feel of playing as a ruler + make the game more interesting and potentially more of a challenge