I tried to do some same platform triangular arbitrage, on paper and in simulation mode my bot was earning a few cents every second. When I started testing with real money I hit a wall when I could not find any platform that placed a bid in under 500ms. My bot was 3 milliseconds away from the server, processing everything in under a single millisecond but the exchange was just too slow to do anything meaningful. In the end I did not lose anything but the fees made it not profitable enough.