SIM swap attack is an old scam trick current reigning again as a means of stealing from cryptocurrency investors' or traders' exchange account of those using their phone number as the authenticator to sign into their accounts.
SIM swap attack is widely used to bypass the platform/service account verification by unauthorised parties, it does not specifically used for an exchange account but beyond that, the usage is widespread across many platforms and services that are not solely for exchange site purposes.
It is known that SMS-based verification is flawed and insecure, one thing that some platforms are able to contribute to secure their user safety is to prohibit or disable this feature.
It is reported that over $13M worth of cryptocurrency assets have been stolen from about 50 people just in 2023.
Where does that number come from, any sources? And who is the 50 people you claimed?