I have very short fingers. My thumb was too short to get enough leverage to get into the big ring. So on my first two mountain bikes I had a grip shift to control the chain rings.

But on my current bike, I use dual control levers. There is only one lever that controls shifting and brakes. Squeeze like a regular brake lever to brake. And flick the lever up and down to control gear shifting.

Some people don't like them, but I really do! Sure it took a little while to get used to them, but eventually it became second nature and natural.