I've been a blood donor for most of my adult life, and have donated about 30 liters. Where I'm at you get a token donation and a thanks for donating, but someone mentioned that in the US you get paid quite a lot depending on the quality and the blood type.
I have a fairly uncommon blood type (about 10% of the population) and a blood count of around 150.
So, how wealthy would I have been if I had donated my blood in the US instead?
You're thinking of plasma, people can get paid for that. Donating blood just gets you a cookie, the satisfaction of helping people in need, and a sticker.
Where I live, the places that do blood donations, also do plasma donations. The process is longer, but is otherwise a similar experience. And since plasma is extracted from blood, it is not entirely wrong to argue that people can get paid for blood donations in the US. It is not accurate, but I would argue the statement is probably based on a truth.
The process might be similar on the withdrawal side, but they are used for very different things. Blood is used to replenish the blood of someone undergoing surgery or who was injured or whatever. Plasma is not given to people. It's used to make pharmaceutical products primarily. So it's the difference that one is a necessity to modern medicine and a hell of a lot of it is needed or people will definitely die and much of modern surgery wouldn't be possible. The other is an ingredient for for-profit products.