The only thing I miss is having the fingerprint reader

XDA Developers

SteamOS now fully supports AMD-based handhelds beyond the Steam Deck, and running it on the ROG Ally X delivers a noticeably better experience. The Ally X offers more RAM (24GB), a 1080p screen with VRR, a larger 80Whr battery, better Wi-Fi, and more comfortable joysticks. Previously missing features like native TDP control, Variable Refresh Rate, and rear button support have been added. The only downside is losing the fingerprint sensor functionality, which is moot since SteamOS boots straight into gaming mode. The combination raises questions about whether Valve even needs to build a Steam Deck 2.

SteamOS runs so much better on the ROG Ally X that I stopped using my Steam Deck

The ROG Ally X has power to spare for portable gaming

The author misses the point of the Steam Deck, pretty much entirely…
First of all, the hardware is by far not only about how powerful it is. It is about maintainability, including repairability and feature set, as well as longevity by itself.
For example, without looking it up, I’m pretty sure, that the hardware community for any modern up to date gaming handheld is probably the biggest or one of the biggest for the Steam Deck hardware, straight up.
Another example would be the obviously missing touchpads below the analog sticks. If you truly made use of them, the ROG Ally X could be 10x the performance, but it would not replace the touchpads.
Further example is, that you get the support of Valve behind the hardware. If something’s wrong, you can use their support. ASUS is famous for offering horrible customer support, not replacing clearly factory-induced broken devices.
If something’s wrong, because you broke it, it can be fairly easily repaired, especially compared to other modern closed-up anti-consumer hardware.
These are just some examples, that immediately came to my mind, while reading this. It’s extremely naive to reduce such handheld hardware only to its performance specifications, when it’s about so much more.