All these months that you’ve been working remotely has your efficiency/amount of work/evaluation remained the same? If yes then you can use this as a valid and

All these months that you’ve been working remotely has your efficiency/amount of work/evaluation remained the same? If yes then you can use this as a valid and measurable point for your discussion with your manager. Try to collect actual data (emails, messages, deadlines, quality...) clearly showing that while you were WFH. As others have suggested, have a plan B during the discussion/negotiations. Can you offer a few days every month? Are you willing to loose any benefits or raises for a couple of years? What about equipment? You have to give something to the “stubborn” employers that don’t see the benefits of remote working, especially for specific jobs that can be performed from a computer anywhere on earth :-) Hope you succeed!