It forces players to remember different positions for the same chord transposed to start at different notes. The piano was developed well before equal temperam

It forces players to remember different positions for the same chord transposed to start at different notes. The piano was developed well before equal temperament came to dominate tuning. [1] So each musical key would have different harmonic relationships between the intervals within it. And musical keys were not thought of as equal. Generally, the musical keys based on “black keys”/“sharps and flats” would be farther from an ideal tuning and there were better and worse sounding keys depending on which musical keys a piano was tuned for. Historically in Western European music, there were preferred keys and intervals inherited from Plain Chant (roughly C,G, & F and octave, perfect 4th, perfect 5th, and the 6th). Of course using an electronic instrument that can be electronically transposed up and down by half steps might be an easy way to avoid learning lots of fingerings. [1] https://www.math.uwaterloo.ca/~mrubinst/tuning/tuning.html https://www.math.uwaterloo.ca/~mrubinst/tuning/tuning.html