Earlier, I would use the Private Browsing feature very often, if I wanted to sign into a different account on a service without signing out of my existing ones. Now, Multi-Account Containers makes it much easier—and I don't even have to re-enter my logins!

Useful for managing multiple sets of logins without having to switch browsers. The "Always open in this container" feature is very helpful: I can make certain websites automatically open in the container I choose. And there's also "Open link in Container Tab" for when I'm clicking on links.