About 9 years ago I did a true range test with Motorola Talkabout FRS radios. The comparison was against a handheld CB radio paired with a car CB radio.

I put my father on top of the local earthen dam then drove away from him using GPS to check distance.

The CB was unusable at 1/4 mi. (summer daytime)

The Talkabouts were still working full quieting at 7 miles.(True line of sight.)

Have also used it to stay in touch with him while I climbed a mountain. He stayed in the valley bottom and fished. Probably had 2 mile range.

Any obstructions such as trees or building materials would drastically reduce range.

I don't know the specifics of the brands but FRS is really convenient and quite efficient so long as you completely comprehend the limitations of Line Of Sight.
(It's what CB should have been all along.)