Binance Zero Confirmation

The idea of fee bumping or replace by fee came in and the idea being that you could add more fee to help it confirm faster let's say. Ultimately miners can mine any transaction we do without the flag any replacement thereof and any node will simply accept it so this is what we mean when we say policy. You may not see some transactions until they end up in a block especially if they were very close to the block but there's like the mempool size for example like it's 300 megabytes by default but if you have a bigger one you may have in your mempool more transactions because you're well you have more space.