The M14 was n awesome rifle... For WWII. It just arrived 20 years late for that.
I really like my M305. I like it more than my AR-15. But as a combat rifle, it was a relic from a different era.
Full powered vs. Intermediate cartridge aside (personally, I'm on the fence on that argument), every other nation had moved on to modern ergonomics and production methods. As a standard issue infantry rifle, the FAL, G3, AK, heck, the VZ. 58... Were all better rifles for the era. Easier to operate. Easier to maintain. Easier to train noobies on. The AR-10, if it had been given even half the leeway and do-overs that the M14 was given during its development cycle and trials, would have easily outclassed the the M14.