Valve make no profit on the consoles themselves right? And if the steam deck profit model of making their money off of games applies to games bought on any handheld, then why not let the other companies have the higher end market and all the research and development costs that making a new console needs. Especially because each new generation would need a refresh to stay on top.(more r and d costs) So why wouldnt valve just keep making their current steam deck that runs stuff well enough for them to keep selling games.
They’re not going to release a high-powered device because they want to wait until the tech is actually there- tech that allows them to squeeze more power out of lower wattages. That’s the whole point of devices like the Deck and the Switch- getting as much performance as possible out of low-powered hardware.
Another thing that would help Valve release a more powerful Deck sooner is better battery tech, which also isn’t really there yet afaik.
But, until one of these things is achievable, we won’t see a new Deck.