Oh but there IS a financial incentive. A big one in fact...
For the past 5 or 6 years Boeing has been very extensively -- but very discreetly -- examining the cost benefit of folding wingtips on the 777x. (There is even a sly hint of things to come in the wording of the opening paragraph on Boeing's page referred to above.)
But the cat has finally almost made its escape from the bag.
Boeing engineers, Boeing market research people, and Boeing aerodrome experts (hint) have all been working hard to accurately assess the benefit and examine the potential market. To understand the cost benefit to users you need to do a bit of research into "Aerodrome Reference Code" (ICAO Annex 14) and "Airplane Design Group" (FAA).
Final hint: What benefits could there be if a hypothetical aircraft could be listed in one category whilst flying but could / would revert to a different category when on the ground?
grizzled