How did I get rid of the small semi-opaque grey/gray dot that has been appearing on my iPad?

Go to Settings > Accessibility > Touch > AssistiveTouch > scroll down and turn off Perform Touch Gestures.

I let my little nephew borrow my iPad and when he returned it to me, it already had that grey dot on the screen. If Perform Touch Gestures is turned on, then the "pointer device" feature will be enabled. Hence, why the grey dot appears on the screen. I find it annoying because I don't use or need it.

I hope this one helps someone out there 😁