This has been an ongoing issue for years now - please add an option to disable Achievement notifications.

Achievements are through Steam. They should be an option I can toggle on and off through Steam in the Steam Notifications settings. GOG has this setting, Xbox has this setting, I believe Playstation also has this setting. Steam clearly has the capability to hide the Achievement notifications, it just needs to give us the option to do so without also disabling chat notifications (and who knows what else).