in the northeast usa (boston, nyc, ohio), staying a couple hours is fine in most coffee shops. and lots of people are interested in open ended discussions. but

in the northeast usa (boston, nyc, ohio), staying a couple hours is fine in most coffee shops. and lots of people are interested in open ended discussions. but we're also wary of getting drawn into something toxic, so you need to be delicate when you say hello - conveying openness without forcing the conversation there was a brief golden age before laptop batteries hit the 10-hour mark when power outlets forced people to collaborate a bit and those conversations "just happened" - it just felt polite to ask people what they were working on it's harder today, but if you're respectful and warm, they still happen. i had positive experiences in paris (and a french coffee shop in mexico) as well