Currently the user's activity feed shows up to 30 interactions over the past 30 days. It makes it a little hard for them to find a specific activity, like a comment, or an answer or a voted item which is not part of those 30 recent activities. Some of the activities like comments, answers or questions should be visible for everyone, but some of the activities like votes should be only visible to the user.
Such a page also helps moderators to make a better decision based on user's activities for example about spams, etc.
Then I'd suggest to introduce a page to show all the activities to the user in different lists like: Questions, Answers, Comments, Votes, etc.