I've been using a few products* of JetBrains on MacOS for the last 3 years, either with 1 or 2 1080p monitors or with an additional 4K monitor but unlike the rest, I haven't had much problems.
There were times the IDEs were consuming too much CPU and were super sluggish as described but then, somewhere in their forums, I found that they have suggested to use the Java suite they have provided with the IDE itself instead the default one and that solved my problem once and for all.
On the other hand, a colleague of mine had suffered a lot from the very same products because of slow disk speed. This is not the case for other ~50 engineers I am working with though and all of them are using new Macbook Pros and JetBrains IDEs.
So I guess it is safe to say that they are usually working OK on modern day computers.
* PhpStorm, WebStorm, GoLand, IntelliJ