Depends on the frequency.

Most handheld "walkie talkie" style radios are in the VHF band (i.e. 30 - 300 MHz). VHF and UHF (300 MHz to 3 GHz). These waves travel line-of-sight only and do not bounce off the ionosphere. If you are on top of a mountain then ya you can get out. But the higher you go in frequency the more the waves are absorbed by vegetation, too. So, that kind of radio is not useful for what you're after.

More expensive HF band radios (3 - 30 MHz) are used by radio amateurs mostly to make long distance contacts. In that frequency, the waves will bounce off the ionosphere. Radio amateurs normally put their antennas as high as they can, to get radio waves to go more or less horizontally towards the horizon, so they can bounce very long distances.

But if you deploy the antenna quite low, 10 feet down to knee height even, the radio waves go more or less straight up and back down again in a more localized area. This is called "near vertical incident skywave" or NVIS. Check out this link: https://oh8stn.org/blog/2018/11/05/ham-radio-nvis-for-regional-communications/ From that link:

In terms of a grid down scenario in large population centers, near vertical incidence skywave becomes critical, where Communications infrastructure has failed. We’re going to use near vertical incidence skywave for communications beyond the the range of handheld radios, usually somewhere local, out to a few hundred miles/kilometers.

That whole blog is all about the technology required for grid-down comms. His emphasis is on digital modes such as "Winlink" (email over radio) and "JS8Call" (keyboard to keyboard chat over radio) as these can be heard and decoded below the noise floor whereas voice needs to be significantly above the noise floor to be intelligible.

Another good outfit is the American Redoubt Radio Operators' Network (AmRRON). https://amrron.com/ They are a radio club based in the western USA (but with members all over) who practice this sort of thing regularly and have a lot of good learning information on their site. I'm not a member, but I read their webpage regularly.

They, too, favour digital modes, but they also have an emphasis on CB, FRS, and GMRS radio which most normal amateur clubs don't cover. The beauty of those is that no licence is required (well, GMRS does but the requirement is light). FRS and GMRS are VHF radios and suffer from the same low range.

CB is just under the top end of the HF band, and often bounces off the ionosphere ("skip shooting") and thus has much of the usefulness of HF radio, without a lot of the technical complications of amateur radio (multiple antennas and antenna "tuners" and so forth) and the requirement for the government to know you have a license. It's supposed to be all-voice on CB, but I have heard people using Morse Code (which is pretty intelligible close to the noise floor). No doubt some people are sneaking-in with digital, too. Talking on CB is sometimes like trying to have a conversation in a noisy restaurant with lots of other conversations going on around you: with only 40 channels to choose from, you are almost always talking over someone else.

The key to radio being USEFUL in a disaster is that there is more to it than just having a radio. You have to have people to talk to, people you trust. No point in just talking into the wind! AmRRON is good because they have a set group of frequencies and modes that they use so they can always find each other.

Find a group like AmRRON (or just have a small group of friends or a church group or something) then decide what frequencies and modes you will use, and practice with your group regularly in battery-only grid-down mock scenarios. Then you will know you have a system that would be workable in a disaster.