This is my whole point. This is only true for some, and it's not distributed according to merit. People get mistreated all the time at both tech and non-tech companies, even in career fields that are traditionally high-paying and high-mobility. The only way to stop that in a way that also promotes a relatively free labor market is for workers to self-organize, and for the government to legally protect their right to do so.
I understand your concerns about communism. Nobody in their right mind is proposing that we bring communism to the USA. The fortunate workers who have market power uniting to support for their fellows who lack market power is not itself communism, nor does it lead to communism. American labor unions are not communism, and never will be.
The USA once developed a strong tradition and culture of organized labor that brought us out of the brutality of the 19th century Industrial Revolution. There were plenty of smaller socialist and even anarchist groups at the time, but in general most people were not that radical, and no group anything resembling the Bolsheviks ever gained popular support in the USA.
Ironically however, communism indirectly enabled big business to crush that tradition of organized labor, because the Red Scare of the early 20th century allowed them to label pro-labor policy as socialist or communist and therefore anti-American and anti-freedom.
If anything, the kinds of labor unions that people join the USA are a uniquely capitalist institution, being dedicated specifically to the purpose of balancing asymmetric market power.