You do that, but it doesn't generalise. Mobile phone ownership exceeded laptop/desktop ownership in the us in the last 2 years and the latter is in a slow constant decline. A lot of people are going to be happy with just the phone in the future.
We went from computers being very rare (early on I remember maybe two families out of the whole class had one at home) to heading to above one per person (everyone had a laptop and there would be a desktop, too, or more) during college and now we're headed back towards "about one desktop/laptop per house or a bit more" as most people have phones.
Literally the top results for US smartphone ownership. You can do it.
> that those that make do with only phones would even want to purchase a tablet or laptop?
That's the whole point - they don't need / want one. But given the services that everyone needs are moving online, everyone needs some level of internet access. This effectively moves windows users to Linux/Android as discussed upthread.
I see. So you're not actually going to even try and answer the question? No evidence? Just "I'm going to conflate desktops and phones to make my point?"