What’s the best portable handheld gaming device in the marketplace?

I’m an Xbox Series X owner I play a lot of games specially call of duty games I currently play black ops 6 zombies but due to the nature of my work I’m currently working traveling abroad very often so I’m thinking of buying a handheld device I have a steam account with very old games that I no longer play I also have Xbox ultimate game pass so I’m wondering if there’s a possibility I can buy a handheld device for Xbox games and steam games as well my budget is not a problem I’m just looking for something I can use while I’m traveling