They are still a lot faster than normal SD cards. I’ve never seen any phone that works with SD Express cards, but there were a few that worked with UFS cards.
If you are a phone manufacturer you can either choose MicroSD cards which are the most common and the cheapest, MicroSD Express Cards which are more expensive but faster and backwards compatible or UFS which nobody has ever heard of.
They are still a lot faster than normal SD cards. I’ve never seen any phone that works with SD Express cards, but there were a few that worked with UFS cards.
If you are a phone manufacturer you can either choose MicroSD cards which are the most common and the cheapest, MicroSD Express Cards which are more expensive but faster and backwards compatible or UFS which nobody has ever heard of.