I find it hard to understand that in a country that tends to take freedom of expression so seriously (and I say this unironically, American democracy may have flaws but that is definitely a strength) it can be legal to silence someone for the rest of their life.
See the assassination attempts on president Jackson.
Its quite common for companies to put tons of extremely restrictive terms in an NDA they can't actually legally enforce to scare off potential future ex-employees from creating a problem.
Though I suppose this is another corporate (really, plutocratic) tyranny.
Essentially your point.
In the US, the wealthiest have most of the freedom. The rest of us, who can be sued/fired/blackballed, are, by degrees, merely serfs.
I’m not sure that this is true. Any employment contract will have a partial invalidity/severability clause which will preserve the contract if individual clauses are unenforceable.