I moved from handheld with motion to tv mode with motion a few months ago. It's helped my wrists (pro controller is a lot lighter than a whole switch), but I'm not sure it's helped my gameplay. I do still use handheld if the tv is taken though.
I do have a slightly odd setup for handheld: left joycon (the rail is loose so it comes out of the switch if you hold it wrong) and right split pad pro half. I did this because I was getting cramps in my right hand from using the face buttons and stick on the tiny joycon.