It's harder to transfer on robotics and biotech as ramping up a projects takes a long time and there's a lot of bespoke tooling. In my experience the jobs that pay the most are where engineers can switch and quickly be productive, as the main force actually driving salaries up are people quitting for a higher pay. The company hiring you for more than average needs you to be productive quickly.

Would you work on increasing ad click rate by 0.01% or on playing with cool tech toys and solving hard robotics problem? This is the same as SpaceX being able to pay under market - what you do matter and people are ready to take paycut to work on intersting problems.

it’s easier to offshore

why? i don’t know, it’s definitely not any easier work. but it’s reflected in the comp

In order to negotiate high compensation, you must be selling something in high demand and selling to someone with lots of cash (or cash equivalent like FAANG RSU). I suspect robotics companies’ cash flow does not look like the FAANG company’s.