I just finished Martin Popoff's Rush bio trilogy. The last one, Driven: Rush in the 90s and in the End, I completed over the weekend. As someone who 10 years ago was a casual Rush fan, I find myself here in 2021 a huge fan, and think the original question about Alex is a good one.
In the 70s, he was absolutely touted as a great guitarist. But as the 80s hit and Rush got more mainstream love, Alex took a backseat a bit right? He went for more color and texture. And while guitars were brought back with more force in the mix in the 90s, he wasn't nearly as "look at me" as a soloist. It was more about groove.
The thing everyone said in those books (his bandmates and various others) is that Alex just goes with the flow. For the last 30 years of his career, he was about the song, not about the solo spotlight. And that plays a huge role in how people perceive him, talent-wise, who aren't as familiar with the Rush catalog and what Alex brings to the table.
He's not a guitar hero. He's a guitar chameleon who changes to fit whatever the situation calls for. Rush were all the better for it.