Apologies if this has been asked, I'm a bitcoin noob. I'm having a hard time understanding how bitcoin scales.
If bitcoin scales massively, to millions or billions of transactions per day, how will mining nodes even have the time to mine for the right hash? All they'll do is spend time downloading and re-downloading (or synchronizing) the new block chain.
Am I misunderstanding something?
EDIT: This question is not exactly a duplicate of this question, mainly because my question is around scalability. If there are millions or billions of transactions happening a day, which is quite easy to imagine if just the U.S. starts to heavily rely on bitcoin (hypothetical situation), I don't understand how mining nodes will have time to increment their nonce and find the right hash that solves the puzzle before the many transactions in blocks start to add up. It seems like the blocks of potential unverified transactions would add up, get backed up, and everything would slow to a halt.
Please correct me if I'm misunderstanding something.