Spotify recently decided to change the default of whether a user is sharing their activty or not. This update doesn't actually solve the issue that the activity toggle is hard to find and unknown by a large majority of users.
My suggestion is to place a toggle and indicator at the top of the 'Friend Activty' sidebar so that users can turn on and off their activty sharing with ease and be aware of their sharing status. This will not totally resolve the issue because a user will need to have the 'Friend Activity' sidebar enabled to see it to start with but it is a start to making this functionality far more accessible and obvious.
An additional change would be to place a 'Share Activty with Friends' button under the 'Private Session' button in the profile dropdown menu with a green check mark to it when enabled similar to what the 'Private Session' button does when enabled. If this is done it is important to make it clear in the settings menu and possibly through hints what the difference is between enabling a private session, and disabling sharing your activity.
Updated on 2022-01-06
Thanks for bringing us your feedback in the Spotify Idea Exchange.
Your suggestion has gathered the votes necessary and your feedback is now reaching the internal teams at Spotify. They're aware of the vote count and popularity of this idea. We'll continue to monitor and check out the comments here, too.
As soon as we have any updates on its status, we'll let you know.
More info on how your feedback reaches Spotify via the Idea Exchange can be found here.