There is very little reason plan anything carefully if the fight is going to last second since micro becomes more important that than macro and even the most carefully plant attack can fail due to a split second event
Hyperbole much? Infantry fights do not last mere seconds. Of course there is a reason to plan attacks carefully if your infantry won't survive for too long outside of cover. It makes flanking, moving from cover to cover, covering fire, using smoke or other abilities, etc. mandatory rather than just charging straight in. That is what makes the game tactical.
Now between fights that last minutes and unit that disappear in second there is middle ground.
CoH2 already has that middle ground. Infantry fights generally last long enough to reward cover and still allow for proper assaults, while punishing bad positioning or just getting caught out of position. And not because squads out of cover get melted in seconds, but because they'll usually drop one or two models before recovering so that they can no longer win that fight.
I say what I see and feel and I see that the infantry is simply melting other infantry.
Absolutely nothing changed in infantry TTK over the past 2-3 years, except for a handful of specific units that had their DPS or durability individually tweaked slightly.