As the French citizen, I can enter Thailand without a visa. According to the Timatic database, which I access through IATA, the entry is conditioned upon whether I can provide a proof of funds. Specifically, Timatic says:
The following should be taken into account even if holding a Visa: Visa exempt visitors older than 12 years must hold sufficient funds to cover their stay (at least THB 20,000.- per person or THB 40,000.- per family). Proof of funds includes Letters of Credit, vouchers, Miscellaneous Charges Orders (MCO) or well-known credit cards, which are honored in Thailand.
What does "well-known credit cards, which are honored in Thailand." mean? Does it mean that if I have a credit card that works in Thailand and allows me to withdraw over 20k THB then it's enough to prove I have enough money? If so, how do they check it allows me to withdraw over 20k THB?