Tags might be hard to differentiate from buttons.
How different should a tag be from a button? A button is a rectangle with a label, a dropdown is a rectangle with a label + a triangle/chevron, a tag is a rectangle with a label and an "X". Which is the problem? Which is the expected confusion for the user?
Also, tags should at best work in all varieties of TagMultiselectWidget, within an input field, as standalones in outlined MenuTagMultiselectWidget.
Examples for different tag treatments at T149391: Build user interface for Active Filter Display Area by @Pginer-WMF