NS- 24m

PS5- 15m

XBS- 9m

PS4- 2.5m

XBO- 1m

For reference here were 2020's numbers:
PS4 - 8.8m
XB1 - 3.2m
NSW -28.3m

Here is what PS4 and XB1 sold in 2014, their first full year:
PS4 - 14.4m
XB1 - 7.6m

Anyway this is my actual prediction:

NSW - 26m
PS5 - 12m
X|S - 7m
PS4 - 3.5m
XB1 - 1m

It's in my signature, but for good measure:

• Switch - 27m
• PS5 - 15.5m
• Xbox Series - 10m

The old consoles... Well, much less than PS3 and Xbox 360 sold in 2014, that's for sure.

Switch - 25m
PS5 - 14m
Xbox Series X|S - 8m
PS4 - 2.5m
Xbox One - 800k

Extremely hard to predict sales for this year

- I put Switch at 25m with It being slightly down compared to last year, but honestly, wouldn't be surprised if it even manages to break 30m mark
- PS5/Series X|S. Still no idea on what the real demand is for these consoles and with supply issues still being a thing until at least summer, it doesn't help to analyse the real demand. If we just take January numbers, PS5 should do around the same as what PS4 did back in 2014, while Series X|S is on a pace to sell better than Xbox One in 2014, but Xbox One was limited to just 13 countries until late 2014
- PS4/Xbox One both will fall behind what PS3/X360 managed to achieve after them being replaced for obvious reasons - backwards compatibility. Back in 2014 for some huge games like GTA 5 for example, you had to buy either PS3 or X360 because it wasn't playable on new consoles. This isn't the case anymore, so anyone willing to buy Playstation or Xbox console will obviously go with newer machines.

Bonus prediction: Xbox One will be discontinued by the end of the year

Switch: 28M
PS5: 13M
XS: 8M
PS4: 2M
XS: 1M

Switch: 29M

PS5: 11M

XS: 6M

PS4: 3M

XO: <1M

Switch 25 million
PS5: 15 million
Xbox Series: 6 million

I'm pretty in line with the OP, in fact my predictions are:

Switch - 25m
PS5 - 14/15m
XSX|S - 8.5/9m
PS4 - 3/3.5m
XOne - 1m

NSW 32.5M
PS5 14.0M
XBS 8.0M

Switch : 30 millions
PS5 : 14.5 millions
XS : 9 millions