Why are people here so obsessed about labeling something by generation? The market does not care one bit whether the Switch is deemed 8th or 9th gen by a bunch of forum-goers.
All that matters is that the Switch is on the market right now and is competing against the PS4 and Xbox One. If those console phase out while a PS5 and Xbox Something take their place with the Switch still being relevant, then the Switch will be competing against them instead but that hasn't happened so there's no sense in arguing semantics over what 'Gen' a console falls in.
The market in general does not care. And the fact that it's even debatable makes the whole concept so muddy that it's not even worth much consideration in the grand scheme of things.