The basic answers for the question in the thread title lie in the Switch and what Nintendo does right now. If you look close enough you'll see that right now Sony can't and shouldn't pull a 'PlaySwitch'.
First of all, the kind of games Sony has right now. Those are totally for gaming at a console. Unlike that Nintendo has way more games that suit mobile devices or both. If you want Sony to make the games they do best right now, that's pretty much a living room experience.
Power. If it's for the kind of games, what people simply expect from Sony or stuff like VR. Sony can't go that easily for less power but mobile like Nintendo did. Instead most will want someting really powerful. I mean we already have that PS4 Pro. That would leave Sony to developing games for two systems again.
Classic handhelds are dead. Let's be honest. Switch is about the size that Game Gear and Lynx had back in the Nineties. The high end devices, that lost over a way more mobile handheld. Why? Something has shifted massively with handheld gaming. Yeah, smartphones are for playing small games everywhere. A handheld basically has to be a premium experience with premium games. Being able to do the Switch is one key here.
Nintendo only managed that by combining the handheld and home console market they've had so far. We can be pretty sure there will be no 3DS successor with Switch being a massive hit. And it doesn't seem like there are still many Nintendo games coming for 3DS.
Sony's only real way to really counter that would be to do one device with less power than the Pro already has and hope that gamers might follow them. While people buy PlayStation for the higher power living room experience. And that after Vita was a failure.
No, Sony shouldn't do a PlaySwitch for quite some time, if at all.







