I think one of the reasons there's not much unionization in tech is that the market balances itself. When your skills are in such high demand, the market has no borders and investors queue to fund startups, working conditions naturally goes up. But it goes both ways. When a given company decides to cut costs or change some working policy you can't blame them, especially when they still pay way above the local median and provide astonishing perks. Also you don't need unionization to have your conditions written in your contract. Certain professions deserve better working conditions, I don't think SWE is one of them,