You can say all that you want about working 4 hours on friday night with uber, but here is the thing, Uber has 100% full control over if you will or not work with them. You have 0 control. Bad ratings? Too many drivers? You come from some nationality that is known for 'bad driving' (pick whatever the fuck you want as an excuse). They have 100% the power. You have zero. If they say: 'if even one person gives you less than 5 stars, you are out of here' and you have no recourse whatsoever.
This is what we as a society want to prevent. This unilateral power dynamic. I'm european. I have seen good unions, amazing unions, and very shitty ones. I'm not 100% pro-union, but I believe that there should be mechanisms to protect the ones with no leverage, because if we don't, the less fortunate will just be modern day slaves to big corporations, only the name will be different.