> If you match a description and are in the general vicinity of where the crime took place, it’s enough reasonable suspicion for a detainment

If you match the description and are in the vicinity of the crime, you are not going to save yourself by talking to the police. You are already in "get a lawyer" territory.

I'm not in the US, so maybe things are very different here, but I still wonder if the absolutist advice is helpful in situations like this:

One night, while walking, I was stopped by police because I roughly matched the description of someone who had burgled a house nearby. They didn't tell me this straight away; they just asked who I was, where I lived, and what I was doing. I didn't have ID on me, but I answered their questions honestly. They went to their car for a bit (presumably checking that my name matched my address and/or that I didn't have a record), then came back, explained the situation, and let me go as they had no strong reason to suspect me. The whole interaction was pretty relaxed and cordial, and they didn't contact me again.

Things definitely wouldn't have gone better for me had I made a point of refusing to engage beyond the legally required minimum, and it's easy to imagine how they could have gone significantly worse.

You are detained any time your freedom of movement is interrupted. If a cop calls to you and you turn to face them, that’s a detainment. So you’re correct, you can be detained before they’ve even questioned you.