8th Gen won’t make it; they’ll lose to the 7th Gen by about 5M in the end.
Switch vs. PS4 is done, Switch will fly past PS4.
Switch vs. DS is still a tough call; like I said earlier if Switch has a year like the last (~30M) then it has a chance, otherwise I think DS will prevail.

Yeah, there's no coming back for the PS4 in the US at this point, unless Nintendo is goes suicidal and replaces the Switch this year or someone goes back in time and assassinates the founder of Nintendo before the company is made.

Getting very close now; 3DS + Wii U can practically feel Switch's breath of the back of their necks. The outcome is decided but it's still fun to watch.

We've reached Wii's last big holiday; the next few months could see the Switch lose some ground, but it will only be a temporary setback.

This time next year Switch might have managed to pass the 3DS life time total.
(If this year it sells the same from March-December as it did last year it will be less than 500k from 3DS total)

Given that 3DS is the third best selling system of all time in Japan, Switch breaking ahead of is quite something.

And as 3DS's legs aren't brilliant from this point on, Switch is probably in the aligned lead for good now.

Yeah, I don't think PS4 can catch up now, with a 4 million gap left and it only selling around 20k a week.

Nintendo has no reasons to replace the Switch before 2023. We still have hyped games like Metroid Prime 4 and Breath of the Wild sequel with no release date yet. Sometimes I wonder what is going to happen when the BotW sequel arrives. Probably another worldwide boost to Switch sales, even if the console is going to be at the end of it's lifetime.

About the second option... Well, time machines are quite expensive.

I know there is no rational or sane reason to replace the Switch anytime soon, I can just never entirely stop worrying because Nintendo do occasionally do some incredibly stupid things. Still, I think it is highly unlikely they'll replace it before 2023 at the earliest the way it's going. 2024 would be my personal preference.

Nintendo seems to be enjoying the success. Also, they announced Splatoon 3 for 2022 on Switch, instead of saving it for a future console. That makes me think the company still see some years for Switch.

In other words, PS4 can't catch the Switch anymore. It dropped faster than I thought after the PS5 release.