I even saw an article yesterday indicating Sony is developing something as well. 2 years away, but still, I never thought they were going to try again after the psp and Vita failure (failure is subjective, I still love my psp). I fully believe the success of the steam deck has revived there interest in it as well.
Because it's not the same class of device. The PS Portal is very niche. It's a $200 device that basically just runs the PS Remote Play app.
I've used PS Remote Play on my phone and laptop, and it's just not good in the cases I actually want to use it: when traveling away from home. Even with a good Internet connection it's only "okay". It's utterly useless when in transit (trains, places, etc.), and 99% useless in any public place (e.g. cafe or library WiFi).
These are all cases where the Switch, Deck, and similar devices excel. The PS Portal addresses a much smaller market.
There's the Playstation Portal, which only streams games from a PS5, and does a worse job than a Steam Deck... Which probably explains why so few people care.