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.
Yeah, the ROG Ally particularly makes zero sense to me and misses the point. It runs Windows and it doesn't have the touchpads.
The touchpads really broaden the utility of the console, from being able to select small UI elements in normal programs to being able to play more mouse enabled games (FTL being the most recent for me).
And Linux is the real special sauce - nobody seems to get why Valve did all that work rather than "just" putting Windows on it. Windows isn't a selling point (you can put it on the Deck if you want), it's slow, the UI doesn't work well on that screen and you lose out on being able to suspend games etc.
I'm glad to see some variation in this space (I almost said innovation except that it's a combo of the Deck and Switch). But it's still running Windows (see above) and it's going to be around twice the price of a Deck.