I work at a FANG in the EU and was previously with them in the US. I make a 1/2 - 1/3 of what i made in the US. I work on same team, same long hours, exact same demands and responsibilities. I ask myself this low pay question every day. I suppose it’s because they can. However, here I have job protection. My team was hit hard by the layoffs and I still have my job thanks to EU labor laws. The healthcare is also wonderful. We never worry about the cost of medical care and with young kids it’s a relief. Those are 2 benefits I’m okay to trade for lower pay, but it’s still super low. Since inflation has shot up we feel it now where as before the salary seemed more in line with the cost of living.

Which city are you located in? And which US city are you comparing against? From what I've seen, the difference between locations at FAANG are pretty well correlated with cost of living.