If they don't have it out for you to start with, answering their questions can get you out of it. If they pull you over and you just answer their questions, the odds are that they will just send you on your way, eventually.
But if you start invoking your rights and they think you have something to hide, they can easily find an excuse. "I smelled alcohol" is a popular one. If you refuse the test, they can invoke the smell of alcohol as an excuse to bring you in. They will eventually let you go, but that's days rather than minutes.
Police will correctly tell you that they don't want to harass you and it is much easier to simply answer their questions if you have nothing to hide. You don't have to, and most of the time they'll still just let you go as long as you comply with the actual orders. But it's not a guarantee.
Every interaction I've had with the cops has been something like:
Cop: I pulled you over for speeding. May I have your license and registration please.
Me: (Hands over documents)
Cop: Where are you headed tonight?
Me: On my way home
Cop: Have you been drinking tonight?
Me: No sir.
Cop: walks back to his car, does whatever they do, comes back with either a ticket (which, honestly, I deserve) or a warning.
That's not to say there's never a situation where remaining silent and lawyering up is your best move, but I do not see how refusing to answer these questions or blustering about "my rights" is going to result in any better outcome in a typical roadside traffic stop.
If you're heading home then he'll want to know where from. Oh, a restaurant? Did you have anything to drink? I smell alcohol! Step of the car please. That's one way it can go, and then he can say you were wobbly on your step and now it's a DUI. People have gone to prison for DUIs where they blew a 0.0. You really have to gauge whether the cop is having a bad day and taking it out on you, then figure out how to best respond. I've had very little experience with this, so I can't quite tell you, but you'd want a lawyer's response anyways.
You make up a ton of hypotheticals to support your point, versus a lawyer and a retired detective (video in the link) who tell you explicitly to never talk to cops.
Neither of whom are disinterested. The lawyer wants you to hire him to talk to the cops for you, and the retired cop is earning money by giving his "don't talk to the cops" speeches.
Yeah, this is what I was thinking as well. Of course the lawyer says to get a lawyer. The insurance salesman will tell you how important insurance is. The security expert will tell you about the grave importance of MFA and password managers. The electrician will tell you why it's best to let the electrician handle all of the wiring. The epidemiologist is more likely to wear a mask and stay at home.
It doesn't mean any of them are wrong, but experts in their respective fields are most aware of the edge cases, they might not be optimizing for what everyone else is optimizing, and they cost the most: and sometimes that cost is an opportunity cost, be it time, money, knowledge, etc.
My original reply was an attempt to prove at that.