Does that take 20 minutes? I dunno. Or maybe they're doing paperwork, or playing solitaire, or maybe just wasting your time because they can. The process is incredibly opaque. Even if it's necessary, it's unclear why, and I've never had a traffic stop that didn't feel abusive.
I'm always super placating about it in an attempt to keep it from getting even worse. Fortunately, it has only happened a very small number of times -- all of which were for minor violations that could easily have been "Hey, I saw you do X. Don't do that again." (Which actually did happen once -- for failing to turn my lights on in the daytime. Which was written on a sign. Presumably about some kind of visibility, I guess. But at least they didn't fine me over it, or take up more than 5 minutes.)
Apparently the correct advice is to refuse to say anything without a lawyer, which I'm certain would be the end of the matter. I wonder if it's lawyers (paid $500/hour or whatever) who suggest that advice.
If you look at it from a lawyer's perspective: The majority of my clients who speak to the police(either before or after employing me) have a large amount of trouble. So therefore it is ill advised to speak to the police.
What they are missing: All the people who spoke with police and had no problems.
It is sample bias.
And the whole point is that even in your case, it’s not directly beneficial to you to answer even innocuous questions about your neighbor’s death; at best it doesn’t change any suspicions on you, but at worst there is a chance that your answers could make you a person of interest when you weren’t one before.
Your claim "not directly beneficial to you" is also odd. Not talking to the police and thus not finding out there's a murderer around?
Maybe it's different in third world countries where the police don't care about the public and are just a law to themselves, that's certainly not the case where I live.