I'm not buying a handheld that isn't Nintendo's unless it "replaces" the home Playstation or PC, which is not going to happen anytime soon if ever. Portability is a non-factor to me, so you're going to have to "force" me to buy one through a ton of compelling exclusives.
That said, I predicted Sony to launch two versions of PS6, with the weaker one being a console equivalent to the SteamDeck, and a new rumour is suggesting exactly that. Since SteamDeck sales figures became known though, I'm not confident that a handheld PS6 will compare to even Vita's sales. It'll be very expensive and might not support some of the more demanding PS6 games later in the generation or after the PS7 is launched.
Since generational graphics jumps aren't all that noticeable, and the best looking games keep taking longer and costing more to develop, at some point Sony and game developers will have to stop targeting high specs. It's all just "too much for too little". So hybrids (at least in the style of SteamDeck) make sense here. The lowest common denominator should gradually go lower and lower, unless game engines provide a paradigm shift that requires beefy hardware.