Pay should be based on value. A good manager brings some value to the team, but if they're bringing a lot more than the technical people, the technical people aren't very good (or junior) in which case the manager may be doing some teaching/mentoring from a technical sense, or helping them grow.
I think it should be an exception, or maybe 50/50 where a manager makes more than valuable technical staff. The idea they manage people and that equates to more value is a holdover from non-thought work.
Yes, pay should be based on value, especially value to the COMPANY. Many times staffs complaining about their bosses' decision only because they don't understand that the higher the position, the more an employee is expected to become an entrepreneur, which means they don't (and should not) think like technicians.
And there is one basics that has not yet mentioned here. It's the simple law of SUPPLY AND DEMAND. No matter how good a technician is, it is often very easy to replace with new (often cheap) ones. And even if the new technician is not as good, the COMPANY will often not suffer. So that's the real "value" of a technician.
Managers are OTOH more critical to the business, and good managers are rare, so they create demand, higher salary rate.
But decisions nowadays are made based on standard and procedure, which is designed to suit most situations. One solution is to understand that technology and management/leadership require different skill set. It is e.g. done in Agile-Scrum methodology where a scrum manager can be paid less, doesn't have to be technical and doesn't have the authority like traditional project managers.
But of course, in a minority of situation, a staff who is good in technical and leadership can exist. And he/she should have higher value because he will know more how to deliver for the benefit of the COMPANY. But it is rare, and one issue with promoting a good technician to a manager is that the company will lost a good technician.
Yes, Human Resource Department can sometimes very lousy, so the solution is again the Supply and Demand law: "There is one common and sure way to improve your salary: move to another company with higher salary rate."