Here's a basic math formula:
Bitcoin can only handle 240 Tx / Min.
What happens if 340 Tx / Min hit the Mempool, and DON'T STOP.
Let's start with 0:00 - 200,000 Unconfirmed Transactions. Average Tx Fee is $10 estimated to get included...
At 0:10 - next block, you have 2400 Transactions included in the Block, and 1000 more Unconfirmed - 201,000 Unconfirmed. If you underbid your Tx Fee, just barely to miss that block, you're 201,000th Unconfirmed Transaction.
At 0:20 - next block, you have 2400 Transactions included in the Block, and 1000 more Unconfirmed - 202,000. You're now 1000 behind getting confirmed... and the same scanario of being underbid on Tx Fees happens to 1000 more Transactions.
If this continues to happen, after 24 hours, 240 blocks, you'd end up with 440,000 Unconfirmed Transactions in the Mempool.
You'd end up with thousands and thousands of transactions "not clearing" - bidding up prices on Tx Fees into the Stratosphere to make sure they are included - until people decide not to pay it.
When would this happen? At the next crash... OR this triggers the next crash. Rembmer the B-Crash? HUGE amount of Transactions Unconfirmed (more than currently) and skyrocketing fees to get transactions to confirm.
And "Deciding not to Pay it" means 1 of 2 things:
