Your point only works if the company is stable and the work is keeping that company running, but Google has expanded exponentially every year, it hasn't reached the stable rent seeking stage yet. All those profits were reinvested in the form of salaries and jobs, if those went to the early workers then I'd never have gotten a job there and I'd have to live with a much much smaller salary. Stable rent seeking businesses are a problem, yes, that is the bad kind, but modern tech is too young for companies to have reached that stage.
So with your model I'd have made less money, that isn't good for me. Your model only works momentarily, when you stop growing the company and suddenly start to pay everything to current workers. But all the future workers whose jobs were enabled by those reinvestments would then be worse off, and I'd be one of those workers since I joined close to two decades after Google was founded. By the time I left there were twice as many people working there, their salaries were paid by the labour done by the previous workers, and Google barely pays profits so far so most of this actually went back to the workers, just future workers and not current ones, that is why I can't say that I deserve more than I got, I paid it forward as thanks for those who made my job possible.
Edit: And about unions, did you know that Google also operates in countries with strong unions? I joined the company in one of those. And you know, Google started paying me much more when I moved from that country to a country where unions weren't strong? How is this possible if those strong unions would make me get more? So apparently unions don't make these jobs pay more, in my experience it is the opposite, they didn't even manage to get my salary up to par with my non union co-workers. Unions mostly cares about the median, they don't care about high end workers that already makes a lot, unions aren't for me.