To be fair to LU management, they are currently working with very limited resources, and they have very high demands on those resources given the economic and financial climate at Transport for London. It is very difficult to see how there is really anything in return for them from spending time and effort trying to get this sorted out - the benefits would all be due to other operators and the costs to LU. Well and good for people at TOCs to complain about LU management but one wonders how they'd see it if the situation were reversed. That's before we consider the corporate view in LU that 2D codes are fundamentally the wrong solution to the problem.
The DfT clearly loves e-ticketing because it gives them a speedier transition to getting rid of paper tickets, and thus being able to close ticket offices. It doesn't matter that so far Cubic has not allowed any way to properly check them at the gates - meaning fare evasion (short ticketing or just buying at the gateline) must be through the roof... heavily impacting recovery post-Covid.
I wonder how many stations can look up to see how busy the nearest small shack now is, as people buy tickets from there to get out the gates (or in).
At least the equipment for onboard checks can warn when a ticket has been recently purchased, as can the handheld readers used at gatelines - but given people can just tap out (unless the gates are disabled) they are likely to purposely avoid staff.
E-tickets are IMO a good thing, but boy has the industry dropped the ball on them - and all focus seems to be on them right now, more so than smartcards.