I'm liking the current development here.
I bet he could have if he wanted to.Lombardo did things Peart was not able to do (I bet Peart could not play such fast stuff, so tight, it is an entirely different discipline).
The fact that Peart continued to actively evolve and learn in the late years of his career (especially in jazzier and more metallic areas) is what I find most impressive. No doubt Lombardo is amazing, but Peart was a living force behind the kit.While both are/were very good in what they have/had done, the scope of playing drums by Lombardo is a large country, let's say the USA and Peart's is almost all continents. Not all, because e.g. he did not have the free flow and feel of a top jazz drummer, and he was of course not a top (power or thrash) metal drummer, the type of drummer that needs a lot of stamina because he plays 90% percent of the time the same pattern in a most intense manner, at high velocity.
Lombardo did things Peart was not able to do (I bet Peart could not play such fast stuff, so tight, it is an entirely different discipline).
But I believe Peart did more things Lombardo is not able to do. No offense to the thrash metal genre; but while its style is very difficult, it does not have the need of abilities that are used in Rush. The feel, the different measures, the changes, the type of interaction with the other band members (especially bassist Geddy Lee), the techniques, the patterns, the accents, the whole extra dimension he brought to the music. Very unique imo.
To put it shorter: Rush's music is richer, more original, with much more variation and therefore more difficult. And Peart did that better than anyone else.