I'd rather see the surgery than allow parts of the game to continue in a vegetative state. I didn't even touch on the AI above for example, but few things kill replay-ability of the game's most-used mode like the AI's inability to play in it.
As for "Improving the mechanics of the game may or may not improve the life and fun of the game."...the mechanics of the game ARE the game. Not all of it, but a large percentage of everything that makes up what HOI 4 is are its mechanics. Making the game worse makes it worse, making it better makes it better. That should be self-evident, but you seem to be making a case otherwise.
If you disagree with that assessment, try modding the game so that supply consumption is 100x higher, that naval invasions take 100x more convoys, or that equipment costs 100x the usual amount and see how "fun" it is to play. Same for removing or adding restrictions that warp the game outside of something resembling WW2.
Most of the mechanical complaints are less extreme than those exaggerated examples, but if you broadly accept that alterations like the above would make the game worse (and to differing degrees), it is difficult to reconcile your general position wrt mechanical improvements. The quality of each mechanical implementation in HOI 4 is on a continuum. They could be done better or worse to varying degrees.
The mechanics -ARE- important and I never said they weren't, but focus trees provide new things to do.
So lets assume that we stopped making focus trees with country packs and reworks after La resistance. Then we take 1-2 years just to work on mechanics and the AI. By the time all those things came out, most players would probably have dropped hoi4 because there was no -CONTENT- updates. Updating how supply works or fixing the peace conference is not content. All the content is the Focus trees, the events, the goofy formable nations and the like. That's content because it allows you to do -NEW- things instead of things that have already been done. So after the 1-2 years of AI and mechanic improvements, then thats another year or two to get a content update and then back to mechanic fixing and such. Thats four years for any new content. Hoi4 would not have a very active playerbase at the time by a logical standpoint, because the game would have gotten stale and boring since everything has been done and completed. There's nothing new to try and achieve.
I absolutely do want some mechanic updates and updates to the game that isn't reworks, but I also realize that I need content updates as I'm getting bored -right- now. I've done pretty much everything that I've wanted or can do myself with my player skill and updating how the supply works or having the AI do better naval invasions, wouldn't really add to the games content for me. Now a peace conference update could open up some new possibilities but more than likely, I'd slow down my Hoi4 gaming.
This is a strange view to take.. I don't see how improving the mechanics of the game wouldn't improve the "life and fun of the game". By definition, improving something makes it better.
The person you responded to is talking about major gameplay mechanics, not just "minor itching" as you so dismissively put it. To be honest it seems like you're just an apologist for Paradox consistently ignoring major gameplay and AI flaws/oversights. This is not the way that games grow in a constructive way, by just telling the devs over and over again "nah it's alright, you guys don't really need to fix or change anything with the game, just give us some more shiny focus buttons, they're nice."
Read above. No one is apologizing for Paradox. Mechanics and AI improvements are not content updates. Focus trees, events and formable nations are content and content is what keeps the game fresh. You can update all the mechanics and AI you want, but the game is still the same and it's already all been done and no point of even playing again just because the AI became smarter.
I've already formed the Roman Empire as Italy... why would I bother again just because USA can naval invade better? That's what I mean by it wouldn't add any life to the game to improve such things.
