My understanding of how legal billing works is that you aren't actually buying one person's time for $600/hr, but you're buying a team of junior paralegals, legal secretaries, and young associates and one big-name attorney to supervise them. The big-name attorneys make a lot, but nowhere close to $600/hour; even if they're partners, a lot of money is going to the salaries of the paralegals, legal secretaries, and $160K/year associates under them.

Is your lawyer an in-house general counsel? Probably no. Do you require this person's services for ~40/hrs per week, every week for years on end? Probably no.

I would certainly pay an amazing engineer $600/hr if I could call on them at any time and get billed at increments of 6 minutes, but that would be an insane way to build software (I know lawyers who think its an insane way to do law, but it is the system).

Because there are less lawyer than engineer. You can't outsource lawyer from different country.

Source? I'd be willing to bet there are just as many lawyers as engineers.

Different country has different law.