Facebook promises the new style and layout has 3 key advantages for users.
- News feed is wider (mobile too?) and more "immersive" (not sure what that means so see reference below for further info)
- Faster loading times (I'm not seeing that yet)
- Dark mode (for desktop and tablet users)
Messenger Rooms Offers the "Immersive" Experience
"Our community is turning to Messenger and WhatsApp more than ever to stay connected. Between Messenger and WhatsApp, more than 700 million accounts participate in voice and video calls every day, and the number of calls has more than doubled in many countries since the pandemic began." Find out more => Messenger News at Facebook, April 24, 2020