There's a noticeable latency using gmail.com on my iMac Pro, too.
I've always used powerful desktops (Mac Pro, iMac Pro) and MacBook Airs while traveling, and while the Airs aren't very good for video games like StarCraft II, I've never had a problem with performance while doing anything else (I work in VS Code on TypeScript). My unit tests run in ~20 seconds on the MacBook Air as well as the iMac Pro.
I've always used powerful desktops (Mac Pro, iMac Pro) and MacBook Airs while traveling, and while the Airs aren't very good for video games like StarCraft II, I've never had a problem with performance while doing anything else (I work in VS Code on TypeScript). My unit tests run in ~20 seconds on the MacBook Air as well as the iMac Pro.