You can’t just ”sack” people in the Uk without reason, there have been pretty robust employment rights for years.
The problem in the states comes from much older staff on very high paying contracts who are doing minimal work and are a left over from the days of Chrysler.
They are protected by unions, one of these staff members is costing as much as 3 regular workers so they want to get rid of them to add flexibility to the company.
In the uk we still have unions, and protections, you can’t just change someone’s contract or sack them without a reason and there are a massive amount of controls on place of you want to change someone’s contract. Maybe if you work for small companies their interpretation of the rules is a little lax. But you can only be sacked in the uk without reason in the first 2 years of employment, which does not apply to these people in the states they are all very old employees, the USA has much more lax rules for sacking people and normally people can be sacked for no reason at any time in most US companies