Xbox haven't quite got the offering right in the UK. You have the S for, what, £250? Well next to the PS5 at £400, people will just assume it is the old one.
Then you have the X for £480 or so, which is way more than a PS5.
I am not sure if it is casual gamers (or parents) driving these figures, but that cannot help.
Maybe they could just call the Xbox Series X, "the Xbox" and drop the price to £400, then call the S comething like "Xbox basic", and at least people know what they are getting.
Even Nintendo are doing better here, as it is easy to see the difference between the lite, normal and OLED.