Ps3 : 8.92   , XB360 : 7.5  ,  Wii : 9.05
Ps4 : 13.8   ,  XBone : 6.55  ,  WiiU 7.52  / Switch : 8.94

From the above chart.

I suspect that with the "Xbox Series" the attach rates are lower, due to gamepass.

And  yes... ofc it is still salvageable.

I'm just not sure if their current rumored strategy will be the one that really does it.
Like I am not expecting the new xbox hybrid PC, to sell more than the current "Xbox Series" did.

There are rumors of it being much more expensive than Playstation next gen (ei. ~800$ vs 1200-1500$).
I just don't see how a potentially 1500$ box, goes onto sell like 100m units.

According to Vgchartz, the 360 sold around 1 billion games, surpassing the PS3. There is a lot of unconfirmed data on that list, such as the Vita software number and the Xbox One software number. The Switch number is very outdated, for example, according to Nintendo themselves.

Surpassing the PS3?

Googled "how many games did the xb360 sell" and basically got a "MS never disclosed end of life sale totals".
Googled "how many games did the ps3 sell" and got "Total Software Sold: ~999.4 Million (as of March 31, 2019)."

Your saying "around 1bn" that seems pretty close to the PS3 number then.
Which for a console that sold about what the PS3 did... makes sense.

However this again points towards thing I questioned.

"The main point of consoles is not to sell as many consoles as possible but as many games per console as possible. In that regard all Xbox consoles have been very to extremely successful all of them have very high attachment ratios higher than most consoles." - quote

Does Xbox really have higher game sales than other consoles?

I suspect its around the same, back in the day.... and lower now, after Gamepass.

I think Xbox just needs better marketing for their consoles especially the Series S since that's $400 and $450. It's the cheapest current gen console on the market (excluding Switch), so lean into that and put the point across that it will play all the big casual games that last gen won't have anymore along with Game Pass. Like, what are the big games we see all the time in the top selling/played charts? EA FC, NBA 2K, Madden, COD, GTA, Battlefield, etc. Even the more hardcore games such as Monster Hunter, Resident Evil, Final Fantasy, etc. are all on Xbox. Just do better marketing and put the Series S as the frontrunner with the Series X as an optional upgraded Xbox. It does help in Europe the Series X is now cheaper than the PS5.

Wut?? Dude, it literally is people switching sides..

Okay, let's imagine that all of that comes to happen, but they all keep releasing on Playstation, could you please tell me why exactly would people choose the Helix over the PS6?

Jumping off a sinking ship before it fully goes under isn't "switching sides". Phil Spencer openly admitted defeat and threw in the towel and told everyone on podcasts. Games like "Absolum" didn't initially release on Xbox either and this is happening more and more. It's not like it's a choice to leave Xbox when you know you'll get forced off eventually because the CEO is telling everyone they've given up

"People are not switching sides. They are just leaving one platform and going to another".

Facepalm..

The XBox Series attach rates are not lower.  People have been buying a lot of their games digital starting with the 360 already.  Both the 360 and X1 attachment rates are actually a lot higher when you include digital sales.  Starting with the X1 most of their games where sold digitally which is actually good for Microsoft.  Selling games digitally makes them the most profits, you do not have to manufacture and ship games, and you don't have to give a cut of the sales to a physical store.

If they didn't go to another platform they'd have to quit gaming entirely because Xbox isn't selling well enough to sustain itself. VGChartz had their sales at less than 100k for last month. Switching sides is a choice that you make. When it comes to leaving Xbox, there is no choice. It hasn't got long left.