
According to YouTube, Handles are designed for it to be "easier for members of the community to find and connect with each other." Especially for those that do not have a personalized YouTube address, this is going to be a blessing. Instead of a long, jumbled mess of characters, they can now be found with a simple Handle.
Those that already have a concise, personalized YouTube address. They can choose to continue using that as a handle. In fact, YouTube will automatically reserve that as your Handle, but the YouTuber can switch away from it if they'd like to.
No worries, the traditional web addresses are not going anywhere, either. Learning new addresses is not necessary for the viewers that have come accustomed to the regular, old channel names. Links will not stop working. However, the Handles will be used by default on channel pages and Shorts, and other community features.
Handles will be rolling out to all channels over the coming weeks, and if you haven't selected your Handle by November 14, 2022, YouTube will assign you a Handle. You can change it in YouTube Studio, though, if need be.