There are very few cases where the company is not allowed to hire other people. They may have a hard time, but it's generally allowed.

> Whereas the employee is free to go to work for some other company at any time.

And generally the employer is free to fire people at any time. And to forbid employees from working elsewhere.

I don't think your examples hold up to scrutiny.

They don't? Employers cannot fire striking employees. Or fire any that may look like retaliation for union activity.

> And to forbid employees from working elsewhere

That's simply not true.

> They don't? Employers cannot fire striking employees. Or fire any that may look like retaliation for union activity.

Who said anything about that? Scab labor is an extremely common thing. How you come to the conclusion that "the company is not allowed to hire other people to replace the striking workers", I'm entirely unsure. For two very popular examples, both in the air travel industry, both pilot's strikes and ATC strikes have had "other people hired to replace striking workers", with varying degrees of notoriety (being at Boeing, I can't imagine you being entirely unaware of either).

> That's simply not true.

Many employment contracts have "no moonlighting" clauses. Only two states specifically forbid them: Washington, and Washington DC (and Washington's policy only affects lower-paid workers) (https://sbshrs.adpinfo.com/blog/7-faqs-about-moonlighting-po... and https://www.rocketlawyer.com/business-and-contracts/employer...)

Moonlighting is not the same thing as getting another job elsewhere.

The ATC was a special case. It was illegal for them to strike, they struck anyway, so Reagan fired them.

"It shall be unlawful for any employer willingly and knowingly to utilize any professional strikebreaker to replace an employee or employees involved in a strike or lockout at a place of business located within this state. 1134.2."