And VW didn't single-handedly destroy the diesel market; economics and physics did. Almost every other manufacturer was also fudging the tests results in some way. But more importantly, building a passenger car diesel that meets NOx targets doesn't work; by the time a passenger car diesel meets modern NOx targets honestly, the car contains a ludicrous precious metal loading in the catalyst and is only a few percentage points more efficient in terms of consumption and CO2 emissions than a petrol car and the math doesn't add up. Diesel is just not a practical solution for passenger cars; it never was in most ways, but it took the EU a long time to restrict NOx pollution to a sustainable level and expose the physical issues at hand.
VW knew this but lied to customers and told them they could have both. Dieselgate was their attempt to convince everybody the lie was true.
What VW did was to save money from ThinkBlue systems. Not every manufacturer failed the tests, especially the ones who used exhaust gas treatment did pass, and were more economical than petrol engines. After that, the EU changed emission standards and made them more strict, so VW switched to using dual exhaust treatment. Which made the cars more expensive.
What finally killed diesels was the removal of the tax reduction on diesel fuel. Since it is now taxed the same as petrol, there is no more any advantage that can offset the higher purchasing costs of the cars.
In Dieselgate VW got caught, made the supervisory authorities and politicians look bad, which is why the authorities also weren't inclined to sweep it under the rug completely. They just shielded VW from the financial consequences in Germany (German VW customers got shafted).
Blocking GrapheneOS is the useless "pretending" part of compliance. They don't really want to do security, because that would cost money, so they pick some actions that seem drastic, harsh and don't cost them anything to implement. Later, when there is a security incident, they will point to their huge heap of pretend compliance, whine a bit about state sponsored actors, high criminal intent and other obvious deflecting bullshit. But they will get away with it, because they did the compliance dance, so they are obviously compliant and did nothing wrong. Nobody in authority will look twice als long as they are neither annoyed or made to look bad.
tl;dr: compliance in Germany is performative