- Many jobs require travel; often with little to no advance notice. And you sometimes don't get to go home until the job is done. You know how devs joke about how hard it is to accurately plan a project? The same applies here too, but except the cost could be you stuck on the other side of the world, unable to visit family, until you reconcile the gap.
- Even lower upward mobility. There are still manager and project manager tracks most places, but VERY few have technical tracks that match. Oh, and if you choose the manager/project-manager path, expect to do zero technical work AND travel significantly more!
- Lower flexibility in expertise/duties. Most disciplines under "physical engineering" are highly regulated/mature and thus do not change much these days. One not-entirely-contrived example could involve industrial-scale boilers - any engineer working in this world has almost zero room for creativity/innovation, you are entirely bound to 50+ year old industry codes that are insurmountable. And if this is what you do for 10 years, you're going to have a terribly difficult time convincing another company to hire you to design gears or PCBs, etc.
This is a pretty gross generalization. I've known someone who ran single-point diamond turning machines, ~directly working with the metal (or whatever). It is highly specialized and my guess is he made probably mid-hundreds of k$/yr.