Since this seems related to prepping, consider what they're for. There are three ways radio transceivers can come in useful:

1. Local comms within your group, within a couple of miles. Very useful even if there's just a local power outage and cell service is down and you want to co-ordinate with family members around home or town. PMR (Europe) operates at 446 MHz (UHF), has a legal power limit of 0.5W and is completely licence-free. Because of the high frequency (= short wavelength) the antennas can be very small, so handheld PMR radios (walkie talkies) are great for pocketable local comms and can be had very cheaply (e.g. Baofeng BF-V8). In the USA there's FRS which I believe is very similar to PMR.

2. Regional comms: communicate about what's going on in your area or with friends/family nearby. CB radio, which is at 27 MHz (the top end of the HF band ("short-wave"); yes there are other CB bands but they are very rarely used) is good for this and tends to have a longer range than UHF but requires larger antennas (the higher the better). Handheld CB transceivers are also available but tend to be bulkier than UHF radios and their compromised antennas mean that sometimes they don't do much better than UHF. When conditions are right (high solar activity), skywave propagation is possible on the CB band allowing worldwide communication, but this is much rarer than on the lower HF bands.

3. World comms: find out what's going on in the world. Only the lower HF bands and below are consistently suitable for this, and transmitting here legally requires an amateur radio licence. You don't need a licence to receive, though, so you might consider at least having a short-wave receiver to listen to AM broadcasts or amateur transmissions. I wouldn't consider this a prepping priority because in a SHTF scenario broadcast stations might still be just propaganda, and amateur radio transmissions might still be just talking about what radio they're using, what antenna they have and knee and back pain.

Note that in a SHTF scenario, radio transmissions may attract unwanted attention: someone might want to triangulate your position, to "acquire" your stuff, because if you're prepared with a radio you probably also have food. In such a scenario you would have to think carefully about whether transmitting is worth the risk.

Finally, a couple of notes about radio culture.

CB radio has a culture of unlawfulness. In the UK, CB radio became popular before it was legal. As such, there's a culture of freedom and unregulatedness that some people really like. People transmit power levels way over the legal limit and nobody seems to care unless it's interfering with someone else. Amateur radio tends to have a more regulated, polite and orderly approach to everything, so attracts more "band police" and rule lovers. Orderly behaviour is somewhat important, however, when your signals can go all around the world!

Some people start out on CB and move to amateur radio, some stay on CB. Amateur allows you higher power (400W in the UK, 1.5kW in the USA) and access to very many bands (LF, MF, HF, VHF, UHF and beyond) so there's loads of versatility and plenty to do. Morse code (CW) and interesting digital modes are used on the amateur bands (these are good modes when signals are weak) whereas CB, PMR, FRS etc. are only voice.

Since amateur radio has bands that cover every part of the radio spectrum, it seems there's little reason to use unlicensed services (CB, PMR, FRS etc.), so why would you? Because:

• They're more free. Swearing and politics are not really allowed on amateur radio. You do hear some sometimes but it's frowned upon.
• They're more accessible. Anyone can just go and buy a CB, PMR or FRS radio and start using it. No licences, no exams, no faff. And that means you might talk to other people on there who've just bought one too and haven't got a clue what they're doing. Some people hate that. I think it's fun.