Just to give some more perspective….
As an example of a real world situation, I’ve attached a picture of core loading on the session I’m working on right now. The 12 cores are fairly evenly loaded in this example -all at about 35-65%, with the ASIO meter at about 75%. (This is a session with 160 tracks including 16 Groups and 12 FX Tracks).
Going back a few years, there are lots of tests on DAWBench.com showing Cubase to be competitive with other DAWs on CPU efficiency and often coming out the winner. Maybe just in the last few years, other DAWs have advanced in this department and we now have to wait for Cubase to make an advance and be back on top! I guess it’s a constant arms race and don’t forget, Pro Tools had a revised audio engine quite recently so one might expect it to be ahead in the game right now.
I know this is bad timing as you have just bought a new Mac but if you ONLY want to be concerned with plugin counts, DAWBench tests consistently suggested Cubase can run a lot more plugins on Windows. Again, that is going back a few years and obviously there are many other reasons why one might prefer Mac (and I do think it’s a nicer OS myself which is why I’m typing this on a MacBook!).