Mobile hardware is restrict in phones by the complete absence of cooling, and the need to conserve power.
The Switch Dock really just offered cooling and power source. It was an elegant solution for Nintendo.
Thank you for this great inspiration for an Idea. Let's asume NIntendo does a Switch 2 (so another hybrid console with a dock). I've been thinking about how the Dock could be evolved further to make it even more useful for a potential Swich successor.
Having a dock differentiates Nintendo from mobile phones. Part of the reason why the Switch 1 gives so much attention to the Joycon (giving them features like hd rumble, gyro, special buttons to play them horizontally) is to differentiate this area (the whole area around the Switch's main body) from mobile gaming, because that's actually an area mobile phones are lacking in. Nintendo probably sees mobile gaming as more of a thread than Sony's and MSoft's next gen consoles.
So, with this in mind, the dock itself is another way of differentiating the Switch from mobile gaming, in other words, it gives Nintendo another edge in this regard, because they can have their device use more power and therefor produce more performence.
But how could they maintain this edge and even make the dock even more useful for a hypotetical Switch 2?
Cooling would be a great way. Nintendo could use the dock to implement some sort of an extra cooling solution that directly works with the Switch 2. This way they could use a powerful mobile soc architecture for their portable mode and have the same chip run much faster in docked mode with extra oooling and extra power consuption.
That'd be a great and fairly simple way of further evolving the whole hybrid console concept.