Today in the US there are at least 4-5 agencies that oversee companies and their behavior. Laws are now on the books to protect workers. Workers can now sue their employers for violating their rights. Workers have protection of whistle blower laws. Are any of these perfect, no, but these are the true reasons unions existed. It was to protect the worker from abhorrent conditions and treatment. That has happened through the new laws and agencies in place. What we should be doing is forcing the agencies and politicians to use the tax money they took from us to clean up the areas which are not good enough still, not giving away more money to a union which is just another business there to take their share of your earnings and the companies earnings. Unions are a tax on everyone, they are not free, so you are taxed twice for 90% of the same protections, and the other 10% I would argue are not protections but limits on your rights.
I still see places we need it to be better, but that doesn't mean tech is a place for unions. Can you imagine all these 2-3 year post grad engineers getting the title of Senior software engineer and getting the equivalent high salaries or out of turn bonuses for great work now learn they have to wait 20 years to be called senior, can never again get an out of turn bonus or special treatment for going the extra mile. Unions equalize by taking everyone down to the lowest level of commonality, you are no longer an individual you are a cog to be used to further the union leaderships goals, not yours. Sure, you get a few extras for that but I for one don't want to hand someone else my freedom to earn and advance at my pace so they can get what they feel is important.
* edited a few words to make it clearer.