For personal correspondence? Yes. Most of what email was used for, for actual humans in their personal lives, has transitioned to SMS and other apps like WhatsApp, WeeChat, Signal, Discord, and that happened a decade ago.
You see that 90% of the daily volume is sludge and think this is a healthy communication network for humans?
There are other types of non-personal reasons people still use email. I certainly don't SMS or WhatsApp with my work colleagues or any of our vendors.