Even a basic A4 artboard with a few texts & a single image makes the Illustrator lag significantly. I'm running a maxed out Macbook Pro 15" 2017 (16gb ram, 4gb gpu, i7). I don't have issues with XD, Photoshop & Indesign. It's only in Illustrator. It worked fine a few months ago, but now it's pretty much unusable. I'm not sure if it's MacOS's fault or Adobe's. I have the latest versions for OS & Illustrator. The issue has persisted for like 2-3 updates (OS & Illustrator).