Another problem is confirmation time . After that time prices will change.
I agree. It wasn't really like this before and I think this came along with the sudden rise of bitcoin. Back then it was a good idea to buy low from one exchange, transfer to to another that has a higher selling value for the specific coin. Now the transaction fees will kill you and it's not worth it anymore as your profits would just be eaten by the transaction fees
Not just with the transactions fees but the confirmation will kill us also especially if the trader are doing arbitrage trading in bitcoin. Anyways that's why it was called one of the best method is because bitcoin transaction is somehow fast and close to being instant in the past so the method is really effective back then. But now it can't be applied and possibility of just making it worst have higher chance.
One crypto is to one exchange and no switch will happen just to target profit.