[ARC5] Question about charts

[J Mcvey via ARC5]

Why is so much of the pre-war equipment dependent upon charts?For example, the BC654 has a limited frequency range, yet the transmitter dial is not calibrated in frequency, but the receiver in in freq. Why is that?The previously mentioned RLC meter needs a chart, when direct reading dials would have been simpler, IMO. ( I have an ancient RLC meter that has direct reading dials).The heterodyne calibrator is also useless without a chart.Then there is the National log dial...and the list goes on...It just seems like an unnecessary extra step.