Except for the queries that routinely pop up from novices in the industrialized world as well as in the developing world, wherein people (a) already have a board which has the 8255 on it, or (b) already have a plan that includes the 8255.

All this trumpeting about "better" ways is totally bogus. I've yet to see one recommendation that offers advantage in cost over the 8255 without giving up its versatility. Makers of "general purpose" boards use the 8255 because they don't know what the end-user's purpose for the board will be. If yo know exactly what you need in advance, and are prepared to go to production with it, then you can shave off some of the cost by using discrete "SSI/MSI" logic or programmable logic (a CPLD with as many I/O's costs about 15% less than the 8255). If you're not building a board, and don't know what the end-use will be, the 8255 or a similar sort of circuit, e.g. MC6821, offers a way to provide some versatility that discrete logic can't.

RE