Even rog is latest device PUBG doesn't have 90 fps
thats the least of your problems.
Something that pubg company has to confirm is currently 888 gen1 90 fps is not available on any phone.
Yes, this is an example of Xperia 5 IV from The Relaxing End video.
But pubg China version and new state already had the option long ago. It seems to be from a different companies.
This is up to the developer to adjust and allow their settings, not us :/