That's pretty common on HiFi. It's not indicating "remaining" per se, the dB value is reduction from line level - -20dB is a 100-fold reduction in output power.
I actually find it pretty convenient since the dynamic range is actually useful (unlike most phones which have a step-change from 0 to 1).
I'm sure it's somewhat deliberate, "only plebs lack understanding of dBs and log scaling. I'm a refined audiophile! "
I've read like 3 explanations of why dB ratings are the way they are over the years and I still don't get it. Personally I think this is one instance where having a 0-100 linear scale is good UX for volume.
I actually find it pretty convenient since the dynamic range is actually useful (unlike most phones which have a step-change from 0 to 1).
I'm sure it's somewhat deliberate, "only plebs lack understanding of dBs and log scaling. I'm a refined audiophile! "