I agree with most of the comments. This is just a dumb terminal, a WiiU 1.5 and should be cheaper than an OLED Switch. But, then again this is Sony. Where I differ is Sony will also allow this device to attach to their game streaming service (PS+ Premium). The only reason they are currently making this out to be stream from your PS5 only is because they don't want to negative affect any CMA or FTC argument with respect to the cloud gaming aspect that would give ammunition for Microsoft. Not that the case seems to be going well for either regulatory body. But the minute Sony knows there is no way they can throw any more wrenches in Microsoft's attempt to buy Activision is the minute they will announce it will also stream from the cloud.
Beyond that I have to say Sony can be so very anti-consumer. There is no technical reason you can't stream from a PS4 to this device. This reminds me of when Sony cancelled supporting PS Now on the PS3 for no reason other than not allowing a way for PS3 owners to play PS4. Props to Microsoft for allowing Xbox One users to stream Series X dedicated games from their Game Pass Ultimate, further future proofing that investment if you don't want to buy an Xbox Series or can't. While, Sony blocks PS4 from playing PS5 only games that in their PS+ Premium service.