There are several things to consider here.
The reasons why you want an Xbox Series (listed by how important they seem to be for you based on your post) are 1) Hellblade, 2) Halo Infinite and other potential new releases that suit your taste, and 3) 8th gen games that you missed out.
Since the two main reasons why you want one haven't released yet and it's not easy to get an Xbox Series at this point, I simply wouldn't buy one right now.
That said, Halo Infinite will probably release before Hellblade II and Resident Evil VIIIage will surely release before Halo Infinite, so by the time the new Halo is out, you'll have at least two games that you'd play if you had the console, but still not the one that made you want to buy the system in the first place. So the question then is if those games are enough by themselves to make you buy the console or not. If they aren't, then just forget about this dilemma at the moment and keep waiting untill Hellblade II is out. When that time comes, you might see things clearer...
...or not. If you're still unsure about spending your money on a new console, because you don't know if those games you want to play will end up releasing on Switch or the next Nintendo system, then think if your computer is good enough to play those games or not. If it is, Game Pass could be a great option. If it's not, then ask yourself 1) if playing those specific games on release or soon after release is important to you, 2) if performance plays a big role in your decision-making, and 3) if those aforementioned 8th gen games that you missed out are relevant enough.
| If playing games soon matter | If performance matters | If back catalog matters | THEN |
| O | O | O | Series X |
| O | O | X | Series X |
| O | X | X | Series S* |
| X | O | O | Series X |
| X | X | O | Series S* or Game Pass for PC** |
| X | X | X | keep waiting |
*Taking the all-digital route, of course, which I think you don't want, because you would've explicitly mentioned the Series S in your post if that were the case.
**You'd not necessarily have all the specific past games you'd want to play, but you'd have others that might interest you too.
If, at this point, you just decide to wait, you'll then need to think of how probable is that those games you want to play end up releasing on Switch. The more you wait, the more accurate your speculation will be - but it will never be anything less than that: speculation.
And if, all things considered, you just don't want to keep waiting to see if those games finally make it to Switch or its successor, but you want to minimize the sensation of getting pissed off if they finally do, then just buy a Series S and you'll be almost half pissed off than if you'd bought a Series X.
Or just forget about all of the above and do what your inner self tells you.
I'm mostly a lurker now.
