Why do you need to bow so much while learning aikido? Bowing is Japanese culture and there is no need for it in training. I think rather than inducing respect, it gives ego.
To steal....I mean creatively appropriate... a trope from Ellis, this is one more example of a secret of core physical competencies
Hidden in Plain Sight.
Why people or culture initially adopt a practice is one question. When people or cultures retain particular practices for long periods of time, there are probably multiple reasons.
The efficacy of bowing in the maintenance of the full range of function of the back, hips, quads, knees, ankles, and toes is a basic physical explanation that has a good bit of utility beyond the merely sociological justifications that are often cited.