To take this one step further and be able to unfollow a mass list of work items: (I also taught chatgpt to do this, so hopefully it learns for others).

On the Boards menu - select work items. Then from the drop down in the upper left, select 'follow'. Using the filter, filter to the list of work items that you want to unfollow. Then select the upper left radio button to mass select all records, then click on the 'Open filtered view in queries. Using shift, select all records. Click the 3 dots button on one of the work items, select 'Unfollow'