In terms of range, they are no different than good quality civilian recreational radios from Motorola or similar brand, they are simply designed to be more weatherproof and carryable when climbing or skiing outside. I don’t remember which frequencies, but there are a couple of channels on these radios that have more power than the others, those are the specific channels you need to use.
These types of radios are popular for backcountry skiing to communicate within a group where you need to be separated in avalanche terrain, but in that use you’re still usually dealing with fairly close distances and usually line of sight, or at least not large terrain features in between people. If you’re in the same basin without ridges in between, you might see up to a mile or more depending on vegetation, etc. You might cut that by a lot if there’s terrain features and whatnot in between. Backcountry skiing here in the east where we deal with a lot of thick trees and small terrain features, it’s not uncommon to have range interrupted after 1/4 of a mile—thats 400 yards. In other places, we’ve gotten good clear communication at several miles.
Beyond that you need to have a more powerful radio that requires an FCC license. The professional level radios used in terrain like that usually require a repeater and a license, and still have poor transmission in some places.
For what it’s worth, I have found my Inreach to be more reliable for communicating if I’m separated while hunting, as I’m usually a ways away, some times several miles, from my hunting partner. I also still carry radios a lot, my most frequent use at this point is fishing rivers with my wife, so we can fish separately but still communicate over the noise of the water if we’re separated by several hundred yards or more.
Edited to add:
The regulation is this:
47 C.F.R. § 95.567 — FRS transmit power"Each FRS transmitter type must be designed such that the effective radiated power (ERP) on channels 8 through 14 does not exceed 0.5 Watts and the ERP on channels 1 through 7 and 15 through 22 does not exceed 2.0 Watts."
I know my radio owners manual specifies which channels use 2w vs .5w. So you basically just need to be on a radio and frequency/channel that is using 2 watts of power, in order to maximize range. If you’re on the wrong channel it will limit the range.