Here’s my take on this.
When looking at ways to monitor an iPhone, there are essentially two main routes you can consider, each with its own set of trade-offs.
The first involves using Apple’s native ecosystem. If the device is signed into an iCloud account you have access to, you can often view synced data like iMessages on another Apple device. The Find My app is another built-in tool for location sharing. The upside is that this requires no third-party software. The downside is that it might not provide a complete picture, as it depends heavily on which iCloud services are enabled.
The other route is using a dedicated third-party monitoring application. These services are specifically designed for this purpose and often provide a more comprehensive dashboard for calls, texts, and location. However, they usually come with a subscription fee and require a setup process.