See, I agree with you on everything here, and I even used to hold this same position:

But I don’t think intellectual cowardice / laziness explains all centrists.

I really, really wanted to be charitable, as a former conservative, as someone who grew up in the deep rural south surrounded by hardline conservatives, and then flipped a hard 180-degree later in life, I figured my own unique perspective allowed me to see both sides.

Then the fire nation attacked.

And by that I mean covid happened, and with it came off a lot of masks. Now I believe that not only is centrism intellectual laziness, so is ALL political dysfunction. It's as close as I will get to a twinge of centerism myself, that I have seen into the hearts of people and have seen that they share a common factor that unites us all: laziness.

It's too broad of a term, and would take an essay to define properly in this context, but at heart it's what drives everyone, a desire to avoid challenge.

Learning and becoming politically astute to even a grade-school level takes some amount of effort and self-improvement and betterment and study and acceptance of new ideas, and we have left the age of self-challenge. Just look at the state of video games with quest markers to do anything, and 30-second popular video clips for the shortest of attention spans, or make a comment more than three paragraphs in a popular forum if you need evidence that people are not out to challenge themselves broadly. They set into a position that feels comfortable based on who they're around and who validates them, and they generally stay there. We don't celebrate people changing their minds, if anything people treat it with shame, and not without good reason. I have been shouted out of leftist spaces for saying I used to be right-wing in some of my views. (Purity testing appears to be another common trait.)