These days I suspect that something like a toughbook might be the only option for those sort of ports - although that GPD Micro PC does look quite fun.

Even 10-15 years ago, proper serial ports were becoming extremely rare, but there are times when you need a proper one.

Around that time we resorted to pc card/express card serial ports for occasions when USB to serial isn't good enough, although they were relatively expensive (3-4 times more than a USB serial dongle).

(The use case in that scenario was field engineers connecting to a very wide variety of odd equipment, like fire alarm panels and door entry systems, that sort of thing - USB dongles were massively inconsistent and unreliable - different dongles would be compatible/incompatible with different kit, was a right mess).

Obviously, these days, express card slots are also quite rare.

(The alternative is hauling out my old IBM T22, which I think maybe came with Win98... mostly still works apart from the battery).