Early showings of Xbox Series X were marketing. CGI renders, empty mockups, and Phill bragging how he has brought home new console to play BC titles.
However, on the games front, they were forced to constantly show PC footage, with real console footage coming very very close to the launch. To me [and many others] it was clear that something was off when they showed Halo Infinite running on PC.
On the other hand, PS5 devkits leaked ages ago [blurry pictures from dev studios], we got regular praises from devs about the state of the tools, and when PS5 presentations finally came, all games [except opening game FF16] were running on actual hardware.
Xbox One also came out hot with games running on the almost desktop version of [high-level] DirectX 11, with low level console API being released later.
They'll iron out the issues in the 1st year.