Back in 2019 I would think a sales timeline like that would be absolutely ridiculous but now it's not that out there to me. Just seeing the Switch keep up with the DS during its peak for several months in a row is making me think it outselling the DS and PS2 to become the best selling console is a possibility. Also seeing that if the Switch ends up having similar declines to the Wii that it would still get above 130 million at this point is making me realize 140 million is likely the floor now since it shouldn't get abandoned that quickly. It'll heavily depend on when the Switch 2 launches but if holiday 2024 is when it does then there should be a real chance at beating the DS.
This week the thread asking when Switch will pass the PS4's lifetime sales got bumped and I had voted for "second half of 2024" a long time ago. That Switch would eventually beat the PS4 has been a given since spring 2017 in my opinion, and Switch was on track to pull it off. But this year's sustained uptick in sales rate will make it happen sooner than 2024, especially in combination with Sony's decision to move on to the PS5 quickly which in turn puts a lower ceiling on PS4 lifetime sales now.
There was another interesting thread earlier this year that asked if Switch can sell 150m lifetime; that was bold at the time (come to think of it, probably a tbone51 thread). If I remember correctly, I laid out the maths that if Switch can average 17.5m per year from 2020-2023, it would be at ~120m by the end of 2023, giving it a shot at north of 140m due to the length of its lifespan. About half a year ago an average of 17.5m per year seemed too optimistic for most people, but now it looks like a piece of cake with both 2020 and 2021 set to finish far above that average.
Which also means that my post from five months ago will have been to pessimistic as far as people realizing what a beast Switch is going to be: