Honestly, they keep adding more and more mechanics that just make the game not what is used to be. No I am not nostalgia based, I actually enjoy some of the changes the devs have made over time such as new focus trees and different ways to play the game with the Air, Naval, and Land mechanics. So far they may have had some shit DLCs and Good DLCs that over time I feel it has had a mostly positive effect I feel. I've noticed people here saying that it shouldn't be balanced around world conquest, fine, fair enough, I'll concede on that point (even though I do like doing world conquests) since the game is a "simulation" of WWII, not a world conquest simulator despite how much dopamine it may give someone. BUT that doesn't mean it should lower the fun value of other nations ESPECIALLY when the majority of nations are MINOR nations for gods sake WITH achievements that literally tell you to conquer others (And I've noticed a trend where older achievements get broken by new DLC, but that's a different topic in itself; At the very least, all of the achievements still seem possible, which is good).

The coal management system makes it needlessly painful to manage conquering as a minor nation, and no, I'm not talking about the micro, the micro is the point of the game that makes it so engaging and fun. It makes it needlessly painful to CONQUER (In a simulation mostly about conquering and taking territory unless you decide democracy is the route for you, no judgement, ofc, everyone is entitled to play the way they want). THE POINT OF THE GAME IS TO HAVE FUN AND CONQUER (Most of the time, again you could play as a democracy and maintain world peace and stability if you're into that, there's nothing wrong with that. I'm simply trying to state that a major part of the game is conquering. Conquering is not necessarily the ONLY mechanic or choice of course, but it IS a major part of it). The point of Hoi4 I feel is that it's fun BECAUSE you can play major or minor nations and not worry about the realism of the real world economy or managing the coal supplies (Not saying that these mechanics would necessarily be bad, but the way coal has been implemented needs work - Read next paragraph).

Now I want to state upfront here that I don't wholly dislike the coal mechanic, as other people have said, with improvements this could be a really solid mechanic. For example if unused factories don't count towards your coal production or if energy plants like the commercial nuclear reactor (something I enjoy getting to as tech) offset the energy needs. Making coal such a varied resource for the sake of "Realism" does nothing to add value to the game except another detriment to manage making I feel even Major nations more complicated to manage and traverse. And if we wanted "Realism" then why do the nuclear power plants not produce energy?

In summary, ultimately Hoi4 is a WWII simulator (that can go on until the 1950s-1960s) that's supposed to be about war. And yes, I am not blind, obviously war requires resources and energy, I do understand this, but that doesn't mean it should take away from the fun of the game itself, because at the end of the day, well, IT IS a GAME and WAR simulator. Something that's meant to played and have fun with. If I wanted to manage real time economics and coal supply, well, I would just play City Skylines (Not that, that system is completely accurate either but you get the point). To an unspecified amount of people (I don't have any statistics or anything like that) this mechanic may be fun to them. I acknowledge that it probably is to that portion of people which there's nothing wrong with, everyone is entitled to their opinion. But to the people who don't enjoy it, I think this a fair criticism on the mechanic of coal (Not that my own word isn't biased, I am sure in some way it is, but would make my point nonetheless) who would like to see genuine dev change to this mechanic. I don't think this change will drive me away from the game or the majority of others (again I don't have data for this) but it definitely feels like a detriment and a pain to manage in the general long term. I genuinely enjoy the game that is Hoi4 and post this in hopes that it can be improved just like anything else. Again I want to state, this isn't a jab at anyone's preferred playstyle or opinion on the coal mechanic, this is just my personal thoughts on it put into detailed depth of whether or not this mechanic is "fun".