I was in my permission dashboard and discovered ImsService (which is a system app as far as I could see) has both location and network by default.
Not only that, ImsService is consistently accessing the location about every 5 minutes.
What is this Service? Why does it need my location so often?

    CoffeeTime03 please leave System apps alone, we can't offer appropriate support where system apps have been interfered with.

    For a run down of what IMS Service is and does please familiarise yourself with the following articles from AOSP documentation:

    From Android 12, Android includes support for TS.43 Service Entitlement Configuration, a GSMA specification that defines the entitlement verification step for the activation of services including, Voice-over-Wi-Fi (VoWiFi), Voice-over-LTE (VoLTE), SMS over IP (SMSoIP), On-Device Service Activation (ODSA) of eSIM companion devices (associated with the requesting device) and data plan information.

    Source: https://source.android.com/docs/core/connect/ims-service-entitlement

    Implementation: https://source.android.com/docs/core/connect/ims

    CoffeeTime03 It's a core part of the cellular service implementation. Location means location data not GPS specifically and information on the cellular network is largely considered location data. Location data being accessed does not mean trying to determine your location but rather accessing data with sensitive location information. This is part of the OS implementation alongside other core components.