The historical answer to that is it was restricted in Europe originally, and by the 1948 eastern Europe was under control of communist parties and western Europ

The historical answer to that is it was restricted in Europe originally, and by the 1948 eastern Europe was under control of communist parties and western Europe was on the verge of communists being elected to power in Italy and France with militant labor unions existing (with the Labour government in the UK nationalizing much of the country). Compromise on wages, organization etc. was the watchword. The US history was separated and a little different. The New Deal compromise was from 1933 to the 1970s, and has been somewhat rolled back since then. The average inflation-adjusted hourly wage has fallen in the US since the early 70s, so the average US worker is worse off in that respect than they were a half century ago.