I can understand how experienced leadership of a large scale multinational corporation should be compensated more than 5x the amount of a 16 year old part time cashier in a town of 2200 people.

I can't. Large scale multination corporations shouldn't exist. But that's a separate issue ultimately.

How much more should someone make doing the same job for 40 years than the new hire with no experience? In a lot of fields, I don’t feel like it would be unfair for that scale to go 4:1.

A company hiring somebody with 40 years of experience should be paying towards the higher end of the 1:5 ratio. It would ensure far more of the wealth goes to those who actually provide value.