iOS 27 introduces new features, but Call Screening, introduced in iOS 26 a year earlier, has made the biggest difference to the iPhone experience as a phone. The feature protects against a growing number of spam and scam calls. The author had owned their mobile number for decades, making it inevitable that it appeared on marketing lists and robocaller dialing lists.
Despite using fictitious numbers for web forms and the UK telecoms regulator's 1,000 unallocated numbers, spam calls increased significantly earlier this year. Initially hesitant to enable Call Screening for fear of missing genuine calls, the author selected the "Ask Reason for Calling" option earlier this year. Since switching on the feature, not a single spam or scam call has gotten through.
Genuine callers explain who they are and the reason for calling, allowing the user to answer. The author highly recommends enabling the feature via Settings > App > Phone > Screen Unknown Callers.
Source: 9to5Mac · Summarized by HeadlinesBriefing