Some mobile networks have spam protection that’s enabled automatically.
You could also have a “clean” number, especially if you don’t use your phone number anywhere online, haven’t answered a spam call before, and nobody used it before you (or the previous user was a long time ago).
Spam callers can’t robodial literally every number, so they rely on lists of phone numbers that are known to be good/active, for example if they’ve answered a spam call before, if the number has been in a data leak, etc.
Some mobile networks have spam protection that’s enabled automatically.
You could also have a “clean” number, especially if you don’t use your phone number anywhere online, haven’t answered a spam call before, and nobody used it before you (or the previous user was a long time ago).
Spam callers can’t robodial literally every number, so they rely on lists of phone numbers that are known to be good/active, for example if they’ve answered a spam call before, if the number has been in a data leak, etc.