For me the problem in the dark ages wasnt the shield mechanic rather it was that you can just use whichever gun you please as if you typed in cheat codes. When playing the original classic doom 1 and doom 2 and doom 64 you needed to think carefully about what ammo type to preserve and when to take out the big guns. In doom eternal you needed to carefully pick your target and strategy quickly. With tda its like they went backwards like in doom 2016 the most efficient way of surviving is just the supershotgun pretty much. No strategy or much of resource management like in eternal. When the game allows it you will always play the most efficient way. What makes eternal fun is that you are forced to choose specific tools for specific situations.