I’m a SW engineer at Arm, and as far as I know (and what I see on levels.fyi) the hardware guys in the same level (e.g. Staff vs Staff) make about the same as I do. The apparent difference is probably more caused by the type of companies that employ lots of hardware engineers. Chip designer at google probably makes about the same as a software engineer at google, but both make way more than the chip designer at Intel. But Google employs mostly SW people and Intel employs mostly HW people.