My personal opinion is there are 2 major issues with the new levy system.
1- the fact that you get significantly more troops from NK > Count only > Duke only > King level vassals is a problem in and of itself, it goes counter to the spirit of the feudal system. If it was only slightly less, I could accept it has a trade off for the ease of managing fewer vassal (I wont go into the kings vs dukes management issues though).
2- Event troops, particularly the ones at the TOG start date don't seem to take the significantly reduces levies into consideration, we've seen something similar when TOG came out and the 1066 Stamford bridge starting troops for William the Bastard were way too low. I won't blame PDox for the oversight, there are so many variables, it's really hard to catch them all.
That leads me to the goal of the levy nerf, what was the reason behind the levy rework, was it to make blobing harder? If so, it does hinder blobing but only slightly, once I gain a certain size, I'll do most of my fighting with retinues, I may have used troops from levies to fight on two fronts at the same time before I got an obnoxious number of retinue so it does slow down early blobing but only slightly.
Was it done to make large empires harder to maintain? Technically rebel kings or dukes would now have more levies that an Emperor but again retinues will often trump that advantage, beside, with high diplo, it's fairly easy to maintain an Empire content and faction free. It does however encourage going count only (if not NK) and can make a small king or duke too vulnerable to early factions.
Was it done to make prepared invasions more successful? I rarely noticed successful invasions pre 2.0 but, I now see a lot more of them, as it gone up too high? I don't know, I have paid enough attention to tell.
Was it solely done to hinder the AI from blobing? I don't have enough info to tell if that's the case or not, I've seen the different Karling realms gobble up each other often only to break apart after a few generations.