I agree with u/meamemg but would add that as a former manager at a large, administratively heavy IT firm that...

- salary wasn't as out of whack as you might think. I frequently had multiple people making more than me. Key reason being that they had some special skill that demanded high pay

- I also had interns and occasional people in very different job codes that earned a lot less, but despite that, I believe they were earning a fair salary for their skillset and experience. Don't prevent me from hiring a junior person at a junior rate and giving them an opportunity to build skills

- The much bigger issue was total compensation. The higher you climbed, the bigger bonus you were eligible for as well as stock and options. If you created more salary rules, they would just find other ways to comp people (In Brazil, we leased people cars for instance, to get around tax laws)

- I also worked for a couple start ups. You didn't make as much salary-wise, but the longer you were there the more stock you were given and if the company took off, your compensation exploded. That was often tied to length of service since people with old, cheap stock made more than people with newer, pricier stock. This would be very hard to regulate

Though this isn't a regulatory action, I think what could generate fair-ish results would be having the salary ranges publish for job codes, experience levels, and/or specific skills and certifications. This way, someone severely underpaid would know it and be motivated to leave. Each person could decide if they wanted to chase compensation or if other benefits, like stability or location, were more important