Most coffee shops where I live (London, UK, specifically out in West London) are at best 20% full through most of the day, that's a lot of dead real estate not paying for itself.

When I tried working out of coffee shops a bit some years ago the "etiquette" seemed to be ~1 drink/hour to pay for your seat. I don't like coffee that much, so was consuming more like 0.66/hour (i.e. around 2 drinks every 3 hours), and people were fine with that, as it was effectively a rent payment of £20/day, or £100/week, which is a little under what a hotdesk would cost me in the same area but with a lot more flexibility (never pay for idle!), and of course its good margin sales for them.

Of course, they could just say "no laptops". There's a pub chain in the UK that did that (Sam Smith's - no screens, no swearing), but the rule is not widely followed or enforced and where it is the pubs are empty far more than the ones that welcome customers.

For a busy cafe that's always short on seating and struggles to keep up with fulfilling orders, they want nothing to do with laptop squatters.

Every other case I imagine it's desirable to have at least some regulars presumably employed enough to be working from a cafe using modern tech.

One common problem I've noticed is van lifers and other quasi homeless folks spending ~zero money stinking up the place just for the free power and internet.

Now that battery life and cell-tethered internet is so good, some of my favorite urban cafes have adopted a no-outlets no-wifi approach, while still having tons of seating and allowing folks to be present with their computers all day. They just have to provide their own internet and power, which serves to exclude the true parasites while selecting for folks with $$ to spend because they have state of the art gadgets with their own unlimited data plans.