[jules-jules]

I imagine a vendor will be able to choose if they want to be paid in a given crypto asset or USD. If they choose USD and you purchase something from them in the crypto of your choice, Bakkt will exchange it using the exchange rate at the time of purchase. Crypto stablecoins (USDC, DAI, UST, etc.) are the easier to wrap your head around. They are pegged to the USD.

In the future non-USD denominated algorithmic stablecoins will become more important, such as RAI, FAI, etc. This will still take some time for mainstream services like MC and Visa to embrace.

Personally, I have been using a crypto Visa card for some time (Monolith) which is basically a debit card where you top up your card with the crypto of your choice (for me usually USDC or ETH) and and then use it like any other debit card. It's a pretty basic form of adoption since the vendor has no idea that you're using crypto.