"High fee and long confirmed time"
This is what actually happening and leading to the destroyed trades like that. Yeah, there were many coins apart form he bitcoin which we use to trade on the intra-exchangers so that we can grab the quick profit margin earlier but now everything looks fading to me. There was time when the transaction fee was almost nothing and confirmations were instant but with the increase in the prices everything is collapsing and to be honest thats taking out the fun out of it!
Nice observation by the way and hoping that such volatility might just come back soon as the prices are gearing up themselves and the fees are getting reduced. Im not sure if I remembered it correctly but did this happen after the segwit2x launch? Because that was the chain which splitter the whole thing and caused this stability.
I have to say I disagree, I think that high confirmation times and high fees are what allow for there to be disparity in prices across different exchanges. With low fees and low confirmation times arbitrage becomes much easier and more profitable and so it pushes the prices towards parity.