I live in Poland and in general I would say this is true. I've also noticed that salaries are rising at a very fast rate here for engineers since foreign companies have began setting up shop.

That's not how collective bargaining works. The entire company goes on strike if they do that, it'd destroy their entire business in a week.

It's cheaper to just pay and treat everyone fairly, which is what they do not want to do. Imagine if all Amazon or Netflix engineers were on strike.