Steam deck vs rog ally x

First off just I'd like to say sorry I know this has been asked before. I'm new to handle PC. I have a switch but never really use it. I'm really interested in using steam. So I'd like to get something portable. I love portable gaming. I have a ps5 but always play old games on my phone. I play all different games. Which one would probably be better for a newbie or for the long run. I have friends that can show me how to setup the rog ally x or use the internet.