If I lived in whatever city this was in, I would definitely go. The coffee and food quality would have to be top notch since I generally associate anything bitcoin related that succeeds as high quality (I pay and will only part with my sats for good proof of work). The bitcoin themed artwork would be a great touch. Local orange pilled artists could even showcase their work.

If a large enough city, I'd probably go bitcoin only, to be honest. No fiat at all. You could have free educational material to give away or I bet some of the bitcoiner customers would love to help someone that walks in and is truly interested in learning more about bitcoin.

You could have an onsite lightning atm to convert cash/coins to bitcoin lightning but otherwise, there should be no other use of fiat.

Word would spread quickly about this new excellent cafe that only takes bitcoin.