I would not say "with very very ease."
It would take the Switch sales really dropping like a rock, along with the PS5 skyrocketing these next two years for it to become the market leader by 2022.
Assuming the Switch takes a natural decline, I could see it selling 23-25 million units in 2021; Then maybe another 20-22 million units in 2022.
The PS5 will likely be somewhere in the neighborhood of 15-17 million in 2021; And then rise from there to 18-20 million units in 2022. So there's a good chance that the Switch will still be the market leader in 2022, into the early parts of 2023, barring a total collapse, which I just don't see happening.
Plus, consider that the PS4's peak year was just ~20 million in 2017, which was its 4th full year on the market. The PS5's 4th full year on the market would be 2024, and if it has a similar trajectory to the PS4, then it wouldn't truly become the undisputed market leader until that year.
The Switch could be the top dog for a very long time. At least for the next 2 years; Then by 2023, they'll be neck and neck, going back and forth as the PS5 is truly starting to hit its stride while the Switch is on its way out. But if I were a betting man, I wouldn't bet on the PS5 taking that top spot by 2022.