There are plenty of supposed Steam Deck killers available in the portable gaming space, from the Asus ROG Ally to the Lenovo Legion Go and all the Ayaneo and ONEXPLAYER devices in between. But none of them have managed to outright slay the dragon that is the mighty Steam Deck yet.
Bazzite’s great! I’ve been following it closely for about a year now and it’s crazy how good it’s gotten. I currently run the Desktop version on my PC, and have tried the Deck version in the past. It’s great, a lot more capable than SteamOS imo.