At the end of the day, it is neither a matter of fairness or formula, it is a market, supply vs demand. If companies switch to remote working from any location, it will be easier to find a cheaper workforce, the equilibrium will go down. If you don’t like the new rate, find an employer that will pay more. If there isn’t one, then the new rate is a fair rate.

I am not sold on full remote working for most companies. I am not even convinced the little covid experiment demonstrated anything, as companies still benefit from employees knowing each others from before the lockdown. Long term the effects in term of productivity, employee morale or culture may be quite different. A compromise is having more local offices, but even then, everywhere I saw it before, it creates a “them” vs “us” between offices, people feel remote from the centres of decision, etc.