There are reasons for all of this, economic without a doubt has been and is the best idea group in the game, no questions asked, in single player and mp. As someone who has extensively played both, the reason why people dont care to take quantity in single player is that ai is predictable. Once an ai has low war enthusiasm, they will peace out no matter what (trusting they are near 0 warscore). However in mp players will fight to the death and quantity allows you to do so. So while you are correct that the average player might not value certain idea groups the same as mp meta sweats, it doesnt change the fact these ideas are op. I think if they added more idea groups overall, such as the idea groups from idea groups expanded, and maybe nerfed quantity slightly (for mp sweats) it would make the games far more interesting and then you wouldn't get as many posts asking for an ideas overhaul.