I'd suggest doing your research before complaining about this. The V speed rating is relatively new and Sandisk has not refreshed their UHS-II offerings since the V spec was released.
Sandisk's V30 cards are their latest UHS-I cards, and that is the highest rating that can be applied to UHS-1 cards. These are actually capable of almost V90 performance (measured sustained sequential writes of over 85MB/s) and would have been rated as V60 cards if that rating was available for UHS-1 cards (which are artificially limited to V30 as a max rating despite the top UHS-1 cards delivering performance that essentially matches the V90 requirements)
Sandisk's UHS-II cards all qualify for the highest speed ratings available at the time of their introduction. However testing on sequential write shows sustained write performance of over 240MB/s, some two and a half times better than a V90 spec would require. https://www.cameramemoryspeed.com/reviews/sd-cards/sandisk-extreme-pro-300-mbs-uhs-ii-128gb-sdxc-memory-card/#:~:text=II card reader.-,Performance,fast for an SD card.
Note if you compare performance, only one V90 rated card has faster sustained write performance than the Sandisk Extreme Pro UHS-II cards, and it's the Sony Tough card that's middle of the pack in terms of the top performers (most of which are not V90 rated). The fastest sustained write cards on the market are not V90 rated because the spec is too new)
So, in summary a quick check of actual performance would show you that Sandisk's top performance UHS-II cards had exceeded V90 spec before that spec existed. You should be using UHS-II cards for maximum performance in a X-T4 body.