One of the expected benefits of an interoperability standard for transport accounts is the improvement it gives the end user.
Suppose you are a traveller who uses 6 different transport services on a pretty regular basis. This means that (aside from how you plan and buy your tickets) to get a collective view of what purchases you have made and the journeys taken… you need to log into each individual account separately every time you want an update. You then have to somehow compare the details in each screen.
However, if the user was able to link their different transport provider and MaaS platform accounts together (yes, they will have to log-in to each to associate them first) then subsequently they could log into any one of them and get a collective view of all their transport tickets, journeys and concessions.