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.
Because tech reviewers only read spec sheets and call it a day. They usually get the product for free and use it for a day or two, which is not nearly enough time to make an actual review of the product.