Devices like the K6, in order to achieve more functionality at a low cost, inevitably sacrifice some aspects of the user experience. While it offers a wide range of features, they may not be fully refined or optimized, making it suitable for casual use rather than demanding tasks.
Regarding specialized devices, the first priority is to ensure that "communication" functions properly. It's not necessary to implement many features; simply focus on making communication work. This doesn't require manual frequency adjustment, UV dual-band operation, or complex displays, and even a display isn't essential. Many machines use integrated, solid antennas, which may have lower efficiency but eliminate the need for connectors, bending, and deformation. The device should be ready to use immediately upon power-up, and the sound output must be loud enough to be heard in noisy environments. From a purely communication perspective, there might not be any significant drawbacks besides having fewer frequencies and lower power.