According to your theory, there is no point to daven when there is no minyan present — because you can’t discharge your obligation.
I also firmly believe that a person is capable of having kavanah in davening. That most don’t is an indicator of other problems, but not of a lack of ability.
And lastly, if they aren’t paying attention when they are actively saying the words, why do you think it will be any better when they are passively listening?
I believe it is always preferable to daven with an minyen unless it is impossible, and then you must daven without a minyan. But there is always the obligation to daven, no matter what.
I was taught that because of the darkness of the Galus of our generation that it is virtually impossible for a single Jew to reach a level of kavanah comparable to the “worst” minyan.
I am not judging you or anyone else, just repeating what I have been taught about our entire generation, not a Jew here and there – but the idea is that we are incapable of actually davening like previous generations, not exactly but halachally similar to someone who in unable to understand the words and must rely on the Chazzan’s repetition.
During this Galus, it is up to us to do everything we can in order to concentrate during our own davening <b>and</b> listening attentively to the Chazzan.
This is what I have been taught – it may be extreme, but there you have it.