I wasn't even thinking about smart contracts. Just basic real time retail. BTC can't do it, simple as that.

The market has long decided that the instrument for payments is stable coins. That's what people who *actually* use crypto for payments want because it does exactly what they need.

And yes, if we go into smart contract capabilities, then there are even more options. That's why that piece of news about BitcoinOS and Cardano the other day grabbed my attention: they say it does what you just said -- use BTC to operate on a their smart-contract chain, but pay and settle in BTC (through something they call Babel Fees, apparently). It seems like an attractive proposition (if only I trusted the tech and someone gave me a convincing, complete explanation...)

Anything big, like inter-bank settlements, can and will be settled in BTC onchain, that much I think is true. Just as it can be settled in any other reserve assets.