As someone who has made a commitment to shorter scale instruments my whole life,. I have prioritized playability over tone consistently. For a few reasons. A playable instrument is good for motivation, particularly if you are practicing even an electric bass unplugged at home when you don't have much tone to worry about. This means I can really burn on the instrument, and the gain in chops seems to eclipse the sound issue.
Second, I find there are ways of making even a bad sounding instrument sound better. New pickups, trying it through different amplification systems, and learning where to play on the neck for certain tones, how often to replace strings, and where not to play on the neck for certain tones. I bought a 1/4 size upright and yes, it was quiet, but I found that with a Big Twin amplification system, I can make it as loud as a 3/4 instrument loud enough through a combo amp.
Third, if you can get your chops up on a playable instrument, larger, less playable instruments become more playable. It's an easy way of easing yourself into playing with a high action, for example. Get the chops and muscle strength on a low action, and then you are closer to perfection when you have to adjust to a high action.
So far, I favor 30" scale electrics and 35" scale upright basses, I have learned that on the 34" electrics, I can play just as well as on the 30" basses now. Easing oneself into the hard stuff seems to accelerate personal progress, which is what it's all about. The fact that I was able to gig within a week or two of picking up a 1/4 size upright was a huge boost to my motivation to learn that instrument. So. for me, playability is the absolute king because of how it impacts motivation.