Or maybe Starbucks should install a common printer with a fee? The large items policy still makes sense, though
Is that a business they even want, someone occupying a seat for 8 hours only to consume two coffees?
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.