What is the difference between a Bitcoiner relying on their node to verify supply and a Monero user relying on their node to verify supply?

You can do simple verification with Bitcoins supply, but who does? NO ONE DOES. Bitcoin is approaching 1 billion transactions and growing. Infeasible that even a single person has verified them all. Every ten minutes?

Bitcoin noderunners were obliviously unaware of this supply bug that would've been undetectable if exploited. Luck + a single honest anon was all that prevented it:

bitcoincore.org/en/2018/09/20/notice

Everyones node would be telling them Bitcoin supply looked fine, but the exploiter would be claiming spent values twice. Undetectable if you aren't combing through all inputs and outputs yourself and only relying on your node.