I would not classify the Switch as portable gaming. It definitely acts more like a console.
Of course this is ultimately a definitional issue, but there is IMHO clearly a difference. I think rather than "mobile" the distinction might be "touchscreen only" gaming; contra some of the wild predictions I recall on HN about a decade ago, "touchscreen only" has failed to displace all other input mechanisms, because it's honestly not all that good. It works, and can be better than nothing, but I think it's hard for touchscreen to ever attain that transparent "flow" state where controls just disappear, and is table stakes for being a 'core gaming' platform.
So, your kids playing a couple of games proves that touchscreen gaming has in fact displaced all conventional controls?
Someone better go tell the rest of the game industry they're really misallocating their resources.
Dunno about Octopath Traveller, but I have no idea why your kids are playing Captain Toad without the controller, unless you just don't trust them with the controller or something. Camera controls are clearly better with the controllers. Deemo or something like that would be a better example, but it's also clearly an exception.
There are numbers from Nintendo on the breakdown between mobile and dock usage, and they indicate a larger percentage of users play undocked vs docked.
I saw the same numbers. They are from 2017 just months after it was released, back before many Nintendo exclusives had been released and even these numbers show 70% of users spend significant amount of time docked.
Of course this is ultimately a definitional issue, but there is IMHO clearly a difference. I think rather than "mobile" the distinction might be "touchscreen only" gaming; contra some of the wild predictions I recall on HN about a decade ago, "touchscreen only" has failed to displace all other input mechanisms, because it's honestly not all that good. It works, and can be better than nothing, but I think it's hard for touchscreen to ever attain that transparent "flow" state where controls just disappear, and is table stakes for being a 'core gaming' platform.