[zrail]

Salaries are what the market will bear (on both sides). If more companies are remote then first class remote engineers will be able to get more offers when they're on the market and thus will be able to command higher comp.

Separately, if you're undifferentiated then of course anyone will be able to do your job if you're colocated with headquarters or not. The trick to selling your time for more money is to differentiate yourself in a way that creates more value for the company hiring you. Your career is a business that rewards a continuous growth and sales process.