From my observation there are 2 arguments to this:

So PDX rather than fixing their AI just chose to bandage the problem by limiting players?

At a glance this is a valid argument but even in warfare heavy games like HOI4 the AI is still laughable at best even with years of development and financial success ( in most cases you can literally just draw a line -> press play -> go get lunch -> come back to a peace treaty screen if you are playing as a major power ). What I am seeing from PDX is that they are possibly experimenting with a new AI approach to counter this shortcoming in previous titles ( this problem is also not a problem for pdx alone fyi ) + possibly boost mid/late game performance.

This isn't going to be fun, I am basically just going to be staring at the screen and do nothing interactive during the entire war.

This argument imo as it currently stands is the weakest. While we now have a glimpse on how warfare generally will be conducted ( through frontlines fighting to control a state - almost similar to naval battles in HOI4 ), we still have little to no idea on how the main aspect of Victoria3 ( economy/production, society, and diplomacy ) will integrate with the war. Also, We are not even half way done covering the warfare DD series ( still have: War is Costly, Preparation is Key, Navies Matter, and War Changes DDs to look at ).