Earlier this week, Bethesda announced that it will be retiring the Bethesda.net Launcher and moving to Stream.
📣 ATTENTION PC PLAYERS: We are retiring the Bethesda Launcher and moving to Steam.
— Bethesda (@bethesda) February 22, 2022
Here’s everything you’re going to want to know about what to expect and how to migrate your Bethesda Library to Steam: https://t.co/KBBokFeZkt pic.twitter.com/f0KWBqd0kp
Hi there! This is only for the https://t.co/spj7OhagQy Launcher. The Elder Scrolls Online is unaffected by this change.
— Bethesda Support (@BethesdaSupport) February 22, 2022
There is a good Frequently Asked Question (FAQ) available here.