The numbers I have in mind are:
Around 4% costs (surcharge and / or exchange rate malus) for most bank cards, Cembra and Swisscard Cashback
Around 2% for Migros / ZAK
Around 0.5% for Wise
Around 0% for Neon
Revolut somewhere in between the cheaper solutions
Migros is often seen as a good-enough single-card solution. But you leave money on the table compared to specializing card use, one cashback card for domestic payments (Cembra/Swisscard) and one for foreign payments (ZAK/Wise/Neon/Revolut).