It's a very roundabout way of trading, and is probably completely impossible unless you're willing to change how the entire technology works. You'll still have to transfer at some point because you'd want to transfer exact amounts.
I don't even think that people transferring to their other addresses is the problem. It's the exchanges. They contribute to most of the traffic. I'm sure it would make a world of a difference if they all opt into Segwit. Your solution won't work with exchanges either since they don't let people see the private keys.
Exactly. At least, one has to transfer some money onto the exchange first and the fee is to high for that. Moreover, one might also want to be able to withdraw the money afterwards, which would also be hard (unless one converts btc into, say, ltc on exchange and then sells ltc for fiat). I think something major has to be done with bitcoin's technology, we can't just avoid transaction fees forever. Yet for now there are some good ways of dealing with the problem: it doesn't always work, but if you have btc on blockchain, you can transfer your btc to eth (or btc to bch and then to eth, just look at the prices) and then withdraw ethereum to some place where you sell it for fiat or use for other purposes. This way you may pay something like $1-3 instead of $30, but again, that's just a temporary solution. I don't even think that people transferring to their other addresses is the problem. It's the exchanges. They contribute to most of the traffic. I'm sure it would make a world of a difference if they all opt into Segwit. Your solution won't work with exchanges either since they don't let people see the private keys.
