Read the fine print.
Introducing Xbox Series X - our fastest, most powerful console ever.
- belonging to or associated with the speaker and one or more other people previously mentioned or easily identified.
"Jo and I had our hair cut"
- used by a writer, editor, or monarch to refer to something belonging to or associated with himself or herself.
"we want to know what you, our readers, think"
The headline says it all, the reason they say "our" on the small print is because it mentions "fastest" and by clock speed it isn't.
They can say it is the World's most powerful console because it is.