COH3 is missing QoL features you expecting
COH3 is not using new powerful processors to implement new mechanics.
It just feels dated and it is all Relic fault
The COH franchise is a niche game. TBH, there is a finite amount of tanks, trucks, and arty you can simulate. It is the disadvantage to playing an historical game which tries to encourage a degree of immersion, when that franchise extends over 3 iterations in a 17-year period. I am not one of those who believes in change for change's sake. To that extent, the franchise will always feel dated, since there are certain aspects best preserved rather than changed.
As to mechanics, I fear you may be howling to the moon. If anything, mechanics have gone backwards in this iteration and so Crush has gone; arty is mostly unimpressive; DevM has done heroic things to reign in the skillz planes; replays may emerge; spectator mode is silent, Surrender button seems lost in space and the UI is all over the shop.
Audio is now in recovery after being on life-support. Who in the name of Hades thought it sensible to have Machine Guns sound tinny?
I could see the reason for limiting modding if the Shop was selling good, saleable skins and other paraphernalia, but the Shop is off and the modders cannot understand why they are blocked. After all, if a Modder produces a really interesting set of skins, they still could not be used in automatch unless Relic became attracted and wanted to snap up the idea.
Similarly with maps, there is a complete dearth of good maps. Relic should be encouraging the community to make maps, since the evidence over the first two iterations of the franchise is that dedicated mappers and modders can produce results as good as the official Relic devs. And this is where the problem lies, I suspect.
In a nutshell, the current Relic devs must accept that they have their equals in the community: Relic Devs should be supervisors now as much as they should be creators. 4 current Relic Devs come from the community and at least one in the past. That is not an accident: the community is the seedcorn for this game.
Relic subcontractors from the community who never joined their staff included the artist, Rita (B)rush, while some non-Dev mappers had their creations formally acknowledged including WhiteFlash and Onkel Sam, and many other mappers had their creations enter automatch, at least for a while. Then there were the various unofficial balancers including Sturmpanther, who at least understood that in 3s and 4s, asymmetric balancing was antipathetic to those modes, whereas balancing in 1v1 and probably 2v2 is a different matter. But still Relic persists in one size fits all, whereas it is patently obvious that revving up in a 4s, for example, you can't wait for fuel to flood through and build the heavies that 1v1 deprives you mostly. Using the Tiger in 4s is a different concept from using the rare Tiger in 1v1. 4s forces the use of ATGs and arty. 1v1 can't do it all.
Why can't 3s and 4s be balanced separately with some similar units but different values? Cut down on light vehicle play for those modes. That was the big miss for COH3.
And last, as Steel Pact showed, there is a lot more that Relic could have done with inclusion of minor armies including Poles, Free French, Canadians, and sub-units of the German army including the Scandinavians and Dutch - Wiking from memory, although Imperial Dane will no doubt correct me if I am wrong. Partisans could have easily been adopted.