There is that risk, the same as any other card you have in your wallet. Basic NFC is dirt-cheap, about $0.25 per tag. There are more secure PIN-protected tags but they are much more expensive. If your card is stolen, the attacker would have to know what to do with, if they even know it’s a NFC tag. Plus you can rotate the secret immediately rendering the stolen card useless. It’s all about tradeoffs - I am focusing on 100% accessibility and 100% inclusion first, then dialing in the security controls as appropriate.