Regarding FCC-compliant CBs, I've seen them recommended many times in this forum, by several members.
Do compliant CBs work? Sure, they do the job they're designed to do within the limitations of that design and the operating conditions. The limitations on an FCC rig are much greater and occur more often than most people think, and that needs to be considered when selecting a radio.
Let's take what the average American would imagine a CB QSO would be: highway speeds, and different directions of travel. You don't need to do the old algebra problems to know that the range of a 4 watt CB makes for a very short exchange. Even 25 watts on VHF doesn't give you a very long discussion over simplex. If you're traveling in a single vehicle, I just couldn't recommend a compliant CB for that use case. You need more power, just to extend the useful range on the road.
How much power do you need? Not nearly as much as you think. 100 watts is a honking mobile signal on groundwave, and more than enough for the vast majority of users. 40 to 60 watts gives you enough range on the road to have a conversation, perhaps even find some locals off the highway a bit. Whether you do that with a 10 meter rig or a compliant box with an amp, you're getting similar range.
As a big fan of SSB and DXing, I've always been drawn to bigger, full featured rigs, and don't have much use for a regular CB, especially the small AM/FM ones. But, I do see a very good use case for FCC compliant AM/FM rigs. Anyone traveling in groups. From permanent installs for off-road/RV groups to lighter plugs and Lil Wils for temporary comms on convoy trips, these can give you quiet comms that won't bother the folks that don't want to hear truckers, while still having ch 19 AM available. Tone squelch the DX and idiots out, and enjoy the silence. People that have never used radios, or just remember the olden days of CB, are usually pleased with having radio comms in a convoy situation.
With the CCR manufacturers making fuller featured radios in smaller packages, I think CB could have a bit of a comeback, if marketed in the right way to the right people (and that ain't truckers or radio geeks). The smaller the better for installation in modern cars, and with some of these new CCRs doing 25-50 watts, their size makes them more attractive for mobiles than the QT and comparable radios. AM/FM with tone squelch gives you the exclusivity of GMRS, and the openness of normal CB. It's both private comms and social media. That'll help sell it to the new generations.
Any kind of mobile rig is generally going to be compromised in any of several ways; size, power, modes, etc. Figuring out the where, why, and how you want to use your radio will help you get one that you're happy with. (At least until the bug bites you)