I would just get a PS5 if I were you. Yes, it isn’t portable, but you will have a better gaming experience compared to your PC.
The SteamDeck is a nice little device, but it won’t get you the same performance as the Ally or Legion Go.
However, the SteamDeck is more stable, compared to the two other options, although, installing and tweaking games, to have the best performance, isn’t always as straightforward as on the Ally/Legion Go.
Windows on the Ally/Legion Go are both a blessing and curse, you can easily install and play any game with little to no tweaking, but you give up some of the power of the device, because of the operating system (Windows). Also, the battery life is better on the SteamDeck, especially on the new OLED models.
Mine doesn’t have any problems.