Agreed.
I dont know about that. The M-1 was developed in the 1970's (yep, its really that old) to fight the Soviet T-72/T-80. In the beginning of each Gulf War it was instrumental in crushing Iraqi ground forces and its absense would have dramatically increased the duration of that phase. Sure, NOW they seem a bit overkill when everything switches to house-to-house fighting but for destroying Iraq's standing army? It cant be beat. Literally.
Luckily for us, we are willing to spend a huge percentage of GDP on our military so for the time being we dont have to trade one thing to accomplish another. I also think you may be underestimating the effect that being able to transport a carrier force that outguns most nations has on bad guys. AFAIK, there are currently no new fighters or tanks on the drawing boards, but I get your point.