This is simply wrong.

Regulatory agencies are constrained by the laws that Congress passes.

Where there is ambiguity (of which there is an infinite supply) the precedent was to leave up to agencies to interpret it. As opposed to requiring endless new bills to be passed.

Nope, it's right, every single part.

Right now there are over 100,000 rules in the code of federal regulations across 50 volumes: https://www.govinfo.gov/app/collection/CFR

Here is another link for you: https://crsreports.congress.gov/product/pdf/R/R43056/9?utm_s...

Search for "major rules". Think about those.

They are constrained only by what is nowadays extremely broadly written legislation. Just read anything like dodd-frank, written by incompetent fools who left it so broad that it said both nothing and everything (no constraints in practice) - and is now the source of 100s of rules across various agencies.

Yes, precedent, part of my point. The constitution says nothing about it. The first regulatory agency came about 100 years after the constitution - that isn't by chance.

It hasn't always been like this. It wasn't envisaged.