When you're congested and you click "Send," you're actually throwing the transaction into the mempool (temporary queue) waiting to be picked up. Miners/validators mainly look at two things: how much fee you're willing to pay, and whether the transaction will get stuck during execution. So, a very realistic scenario occurs: low bidders are left at the back of the line, waiting for a long time with no movement; if you get anxious and increase your bid, the previous transaction hasn't been packaged yet, and the new one has to wait for the old one to go through, sometimes resulting in "self-blocking." Even worse, after waiting in line for a long time, the status changes (for example, your balance/authorization/price has changed), and when it's your turn, the transaction fails directly, with the fee still deducted and the gains not yet received. During airdrop seasons, this is even more obvious—platforms cheat with points, everyone rushes like clockwork as if going to work, and on-chain activity resembles rush hour... I now prefer to do two fewer steps and carefully calculate the failure costs of each step first, so I don't get robbed of a day's effort by hidden fees.