Twitch have announced they will be removing the Friends Feature on May 25, 2022, this feature is one that they say very few people use. Twitch claim that the Friends list was rarely utilized by most users.
By deprecating this feature, we are able to further focus on building connections among communities while streamers are live. The feature will be removed from the mobile app on May 16, and Twitch.tv on May 25, 2022. After that date, your Friends list and the ability to see which of your Friends are online will no longer be available
They do go on in the official notice to describe how to follow your friends and say that if your privacy settings are to block messages from strangers you will need to Follow your friends to continue receiving messages.