Wait a second, are you arguing that it’s better to just straight up fire people? In that case, the company is absorbing the lion’s share of the profits (or whatever profit is left) so you are effectively arguing in favor of shielding an entity over the livelihoods of the people who work within it.

To butcher a famous poem, it's better to have hired and lost than never to have hired at all. Restrictions on letting go of enployees mean that companies are afraid to hire. They double check and triple check, they reject everyone they feel even the tiniest bit suspicious of, they try to protect themselves with ultra long probation periods, etc.

I don't know about the US, but I spent 4.5 months trying to get a new job here in the EU as a senior dev. Everyone tells me that was quick.

>there is a real risk that what arises is labor immobility and blocking new entrants.

We're already doing that without uniuons. Older folk can't afford to retire and new grads cannot get a leg in to start their careers. we're talking something like a quarter of new grads who cannot get any job in their field out of college.