By default all apps on Android have Network and Sensors permissions granted to them. Many apps don't actually use neither Network nor Sensors to fulfill their operations.
GrapheneOS is different from stock Android. GrapheneOS allows users to revoke these permissions. Developers don't write apps for GrapheneOS, they write them for Android. Developers expect to have Network and Sensors permissions without asking and without any fallbacks.
You, as a GrapheneOS user, have liberty to revoke these permissions from any app. Please be careful when revoking permissions from system apps as you might accidentally break something.
Hope this clarifies things