I dont agree at all, all other coins are useless for transactions if you dont want to pay high fees, they are usable only for MICROtransactions and tiny transactions.
You can buy e. g. doge for 71 satoshi, but you cant sell it for 71 again, you will sell it for 70 or you have to gamble and hope that the coin goes up in value (bad idea when sinking like now). So if you transfer e. g. 0.05 BTC you will pay 0.05 x (71/70) fee = 0.000714 BTC So you pay 7 times more than if you sell directly your BTC and pay 0.0001001 BTC fee. So this way is profitable only for sending really ridiculous amount of coins below approx. 0.005 BTC. But what you will sell for 0.005BTC? Pizza costs 0.015BTC (cheapest margheritta)
You can buy e. g. doge for 71 satoshi, but you cant sell it for 71 again, you will sell it for 70 or you have to gamble and hope that the coin goes up in value (bad idea when sinking like now). So if you transfer e. g. 0.05 BTC you will pay 0.05 x (71/70) fee = 0.000714 BTC So you pay 7 times more than if you sell directly your BTC and pay 0.0001001 BTC fee. So this way is profitable only for sending really ridiculous amount of coins below approx. 0.005 BTC. But what you will sell for 0.005BTC? Pizza costs 0.015BTC (cheapest margheritta)
fees are usually 0.15-0.2 of the amount, so 7x equals 1.4%; now, if an arb opportunity comes up with 10% or more, you get 8.6%; you can afford to waste another 1.5-2% on price difference (it was very seldom more then 3% on doge in the past 4 months); for every percentage gained on arb opportunity you can afford to waste more; during swings you have to watch both sides, and usually, if you're fast, bagholders will dump on your low buy order on the other side, and you can then transfer that back to the original exchange (it is usually much less then the original difference, but hey, you can use it to cover the fees and price difference);
mind you, some arbs opportunities go up to 25% during pumps, so a pathetic loss of 3% on fees and difference really is pathetic;
edit: I mentioned liquidity, didn't I?
edit2: this is only for daytrading, not for one time transfer; scalping, arbing, high-low on ltc etc.