This problem is exacerbated on mobile, where the old window is never visible.
New windows or tabs can cause disorientation, with users often not realizing that a new window or tab has opened.More windows or tabs increase the clutter of the user’s information space and require more effort to manage.
All of these also apply to opening new browser tabs and are still valid today: Since 1999, it's been a firm web-usability guideline to refrain from opening new browser windows for several reasons.