It's definitely responsive enough; performance is not the problem. It is software availability that the biggest problem -- Android doesn't even really have a decent desktop-class text editor. But email, web browsing, games, etc is all fine; I can multitask all these things in a Dex desktop.

I used DeX (the non-Linux version) while my main laptop was in for repairs, and it got me through. There were even positive surprises, like discovering it supported external hard drives and some of my pro audio gear. I could connect my Focusrite Scarlett USB audio interface which is connected to my JBL 305P studio speakers.

If you're able to do all your work on Android or the web, it would work. But for me there's still a ton of Windows and Mac software I need to get the job done. The other problem is DeX doesn't really work in a laptop form yet, and I like to do work from cafes a lot.

The Samsung Tab S6 with the keyboard cover would give you DeX in a laptop form factor.

Better not update it to Android 10 though, as they canceled the project.

They cancelled Linux on Dex but that's not what I'm using. Dex works fine on Android 10.