I have been using Ergon GP1 and GS1 ergonomic grips for 20 years, and bugger the weird looks and rude comments I get. Great for injured/ older wrists and thumbs though I was using them when I was young too. These have been on an Ibis Mojo, Yeti ASR5C, Spot singlespeed, Yeti SB5C, Ventana el Conquistador de Montagnes full-Suspension tandem, and my current ZERODE Katipo enduro and Specialized Stumpjumper 2021. And they are always screwed onto a well-swept bar; Protaper 20/20 (20 degrees back sweep), SQLabs 16 degree, and my new favourite the Whiskyparts Milhouse 16 degree sweep 825mm width 75mm riser ( slammed on the head tube to maximise reach). The Milhouse has been a revelation on the Zerode; seems to make front end grip so much better though I have cut them down to 780mm.
I have never found these ergonomic grips to be an issue on any trail, no matter how steep and rooty/rocky, in contrast to all the anecdotal comments that you can’t use them on “technical trails”. In fact the added support they give to the outer part of your hand is great on the rough stuff and I never suffer the dreaded arm pump as I’m not gripping skinny little round grips for dear life. These things are definitely not just for family cycle paths, commuting and rail trails.
I think the Ergon/SQLab grips are hugely under appreciated as are swept back bars. Don’t knock them till you try them. But be prepared for lots of negativity at the trail head