I don't think the perspectives on unionization in tech are representative of the perspectives of unionization in other industries. Unionization's primary purpose is to increase the price of labor (in the form of wages, or in the form of increased benefits) by constricting supply. The going rate for job Y is $X, but if everyone that does job Y goes on strike and demands $X + $N then they can get higher wages. In tech, though, the demand for labor is already considerably higher than the supply. In my experience, tech unions are not concerned with traditional union topics (working hours, safety, etc.) but instead fall into two camps:
* People that see the use of H1Bs as suppressing wages for American tech workers. This camp is often broadly against immigration in general, and is more closely aligned with the right. You won't encounter many of these in the Bay Area, but they do exist and are more prevalent in other parts of the country.
* People who want to make tech companies even more progressive, often wanting more aggressive diversity representation OKRs and abolishing interviews. Some good ideas are present here (like ending forced arbitration) but this camp is often adverse to meritocracy which runs contrary to the ethics of many, if not most, tech workers.
Really, software development and tech are fantastic jobs that pay well and have effectively zero risk of injury. Hours can be difficult in specific segments (e.g. Game Dev) but compensation as a function of work life balance is far better than the overwhelming majority of other industries.