There are a couple of clues to indicate that it is a software issue.
Firstly, the ring tone at the door is sufficiently loud. This would suggest that the audio channel, amplifier, and speaker are not a problem. No one is reporting insufficient ring tone volume when the button is pressed so far as I am aware.
The second clue is that there was a work-around (that I believe might provide a solution for some, but not for me), is some old Android APK that turned off a time-line feature and then the problem went away. I believe I tried this and it does not work for me, that is not to say it does not work. If it works for some, it is a verification of a software defect. This could be inadvertently changing data on the unit itself, unrelated to this volume issue, and it is somehow affecting some defect in the code, who knows what that is? I have seen stranger things in the field with embedded systems.
If I had to guess, and this is a only a guess, they are running the output speaker and the microphone at the same time and using software tricks to cancel the speaker output to prevent feedback during two way communication. Otherwise, you need to run the speaker and the mic like a walkie-talkie (one speaker at a time) and that is not apparently what they are doing. This would suggest that software is in the mix. It may be they they are unable to tweak the software sufficiently to deal with this and they are not divuldging this. I would be happy if it was not simultaneous bi-directional communication. The problem there is there integration with the Alexa that requires real-time bi-directional communications. Change that and you break Alexa.
What I do know, given 35+ years in the embedded development world is that the current implementation is a big fat FAIL. I would be embarrased if this were my product and the reason is that I am successful (without stacks of gold bars in my offshore accounts) is that I never allow any failures to stand. I would fix them for free if I have to.
What we have here is completely different, they do not care, they have your money, and those bogus advertisements that show remote users yelling to stunned criminals continues. Eventually, sooner or later, this will catch up with them either through horrible PR coverage or perhaps damage relief sought in the courts. One way or another this will have a conclusion.
Whether Bezos is aware of this issue or not I am not sure. If I were him, I would get it straightened out before he gets a bunch of bad press and Ring goes kaput. They have their security products but these video doorbells are part of it. If the alarm is as bad as the doorbell, forget about it.
I have already considered it a lost cause and a $200 loss but I can assure you this is my last Ring product. I wasted a lot of time on this and I will waste no more. I will watch the train wreck from here on out.