Technology changes are not happening as quickly as they used to, so I expect this generation to last a little longer and so total sales will end up easily reaching 100M past the 360 sales. I figure there will probably be a half gen model release (ie: slim version) that will be counted in the sales.

Not exactly fair, without the cheaper S model the graph would be different.

There is a supply constraint issue now the 360 didn't have to worry about. Is that fair? What if there was only one Xbox model without the supply constraint issue? Sales would still be higher than the 360. 

My guess is somewhere in the 65-75m range. It's pretty much guaranteed at this point for it to outsell the Xbox One but properly keeping up with the 360 is probably too much for it to handle.

Yeah I agree with the rest I think Xbox is the most unpredictable currently. Remember software pushes hardware sales, it really depends on how Microsoft uses their acquisition and games + Gamepass. I'm pretty optimistic predicting that this will be the best Xbox console in history selling more than the 360. I guess about 100m.

Multiple factors
1. Xbox having the momentum currently
2. Increase in gaming interest and market, bringing more players to console. However, console market overall hasn't increased since the 360 era.
3. Just looking at their actions, you could tell they are serious this time around. I'm not sure if their profit would be too great, but their revenue should be.

Microsoft doesn't share much numbers related to gaming anymore, but I'm sure they will share data if it passes 100m or 360 to appeal to their investors or let everybody know Xbox is doing good (to create more momentum (just like Nintendo with Splatoon). The only issues are stock shortage and stagnation in the gaming industry at the moment.

We really won't have a good idea on the Xbox Series and PS5's outlook until supply chains can catch up to demand. We also don't know if either company is going to make any more huge purchases this generation beyond the Activision deal. My guess right now is 70 million, but that could be significantly higher due to many factors that we aren't aware of at the moment.

Exactly. The 360 had its own advantages and visa-versa. Saying something is unfair is a strange way to discredit another systems success. 

I said 70-74 million, based on current marketshare trends against PlayStation. I think they need to show greater marketshare improvement over the holidays and 2023 if I were going to adjust that up.

It did 50 million after being sold bundled with cereals and paper towels + having the game pass and the covid lockdown, I mean it spent most of its lifetime being the « meh, why not » console.

Now the Series X is sold for more, and have good arguments, but the PS5 isn’t failing to reach the general audience for now, so it doesn’t seem to be having the same sale logic as the Xbox 360

Many of the issues the Xbone had early on, the Series X|S avoided. There is no argument to be made when the system is clearly outperforming the Xbone and that's with shortages. Why it would sell about the same as the xbone makes zero sense. Series X software will also be much stronger once this gen is all said and done and keep the system much more relevant. The PS5 is very popular, but Xbox is keeping pacing. It's nowhere near as lop sided as last gen.