If you just pay Bitcoin and get paid in bitcoin, you do not need any exchange.
Thats right, Bitcoin is still far away from this ideal scenario though. Very few people earning Bitcoin now, thats why most people need some form of exchange to get Bitcoins. Maybe in the future exchanges wont be so important, but now they are essential for people to get Bitcoins. Would it be better if the exchanges were decentralized and trustless? Yes, but there is no good enought working alternative. Look at localbitcoins, the spread between buy-sell prices is too big, and very illiquid market with just few buy-sell orders available.
There are probably more pople/businesses in Bitcoin than were previously in it. The price has dramatically increased and continues to do so.
I know Coinbase say they insure about their assets. I'm not sure if the documentation for this is publically avaliable by them though or if this is an accurate claim.
I don't think they do. USD may be held in insured accounts, but not BTC. I'm pretty sure I saw a Medium article recently from Fred or Brian in which he stated that insurance was prohibitively expensive, and that they preferred to expend those resources on improving their security infrastructure.
That sounds all well and good, but it is a bit scary to consider how much cold storage they have. I wonder what they would do in the case of a major hack.
If they have a lot of cold storage (which ist sounds like they do). Then that's probably not very secure compared to the value. Unless they have printed paper wallets stored in a large concrete safe, surrounded by armered guards and vehicles, hidden in a bunker, I don't think it's very safe!
Once there's a major hack or breach of their pysical security, then there's a massive problem for coinbase (they would actually be a very profitable hack as they store millions of dollars worth of Bitcoin there).
According to their recent AMA, they have upwards of $700 million worth of BTC in cold storage. Scary as hell, if you think about it:
https://www.reddit.com/r/Bitcoin/comments/4wx23q/coinbase_security_team_ama_10am_pdt_today_here/d6arx2xWe currently have upwards of $700m secured in cold storage. The cost of insuring those funds would be very significant. In our view, that money is better spent on continually improving our cold storage solution.
So indeed, no insurance on that amount of bitcoin. I would concede that insurance would indeed be expensive, but one has to wonder how secure their vault really is. My biggest concern with bitcoin businesses is always inside jobs, and cold storage can't protect from that. I just hope they have multiple strong levels of security / multi-key access to that cold storage. That's a lot of money on the line.
A scary and slightly enticing amount to have stored somewhere offline.
That's a lot of money stored there in Bitcoin, let's hope for sure that they're using very good security measures, otherwise, the majority of everyone's money is gone.