Look guys. I'm not a Rush fan, but I admit. Neil was an incredible drummer. Best of all time is relative to your own opinion.
People speak of complexity, yet some of the best songs in history are not complex at all. So many three cord progressions are iconic. Complexity does not make you a great musician. Great music moves you no matter how simple or complex it is.
A guitarist or a drummer can have a massive instrument / musical IQ, but that doesn't make him a great song writer. It just makes him a great musician.
You have guitarist virtuoso like Yngwie Malmsteen, but (while it's my opinion) he isn't even remotely near being one of the greatest guitarist ever. The guy can play like nobodies business, but all his music is just a bunch of arpeggios. (he is all technical, not lacks real music creativity IMO) Joe Satriani on the other hand is very much like him, but he is a hell of a lot better musical composer to boot. (though he isn't even in my top guitarist ever)
Some of the greatest guitarist in history "technically" cannot hold a candle to either one of them, but they have written more top songs and made a hell of a lot more money than either one of those guys. Joe Satriani is worth $12M, Yngwie Malmsteen ($7.5M))
Not to mention there are incredible musicians out there that none of us ever heard of. Not because they couldn't make tons of money. They choose not too. You would not believe how many incredible studio musicians are out there because they don't want to grind on tours. Hell, Jimmy Page from Led Zeppelin refused to join bands for a long time before he finally joined Cream and then Led Zeppelin. (Watch the Muddy Shoals documentary)
Anyway, as I noted earlier. Opinions are relevant to the holder of that opinion. Many people are a fan of Rush enough to make Neil Peart worth $42M. I'm a fan of Neil's, but I am not a Rush fan. In my opinion (mine), he would have been better served with a different group. Though, I'm not going to complain. Rush has brought a lot of joy to people and that is what music is about.