Just imagine that tomorrow all the big mining farms disappeared. What effect would that have on btc? After the difficulty had settled, absolutely none. Correct me if im wrong but if there was a handful of compuers running the mining software then life would all carry on as normal. btc is like the internet, you take a big chunk out and it carries on as normal. One transaction would be verified every 10 min whether it was 100 miners or 100,000 miners.
Are bitmain, antminer and all the big mining firms and pools leeches on the system?
- As they are so big, the difficulty is higher and it takes more power to mine.
- All the power is concentrated in a few players. Individual miners don't stand a chance.
- Chances are fees would be cheaper as well.
But you are not considering their most important contribution to the network which is to secure it, even if every single transaction was confirmed by a single old computer and everything may seem like the same to you the security of the network will be heavily compromised which means that almost anyone could attack it and begin to reverse transactions left and right, so you are incorrect, miners are not leeches and without them bitcoin would not be as secure or as valuable as it is now.