This site talks at length about running businesses, identifying your target market and focusing hard on them. The same thing applies to other aspects of software.
If I ran a cross-platform app (built on Electron or whatever) and a certain platform made up 0.1% of my users but 20% of my customer support team's time, I'd stop supporting that platform. It's literally not worth the effort. And I wouldn't just let it rot (that would keep the customer support issues going), I'd block it.
> GrapheneOS is a privacy and security focused mobile OS with Android app compatibility [https://grapheneos.org/]
Tools such as play integrity are illegal. Using anticompetitive and monopolistic tools is not the right of application developers.
> Using anticompetitive and monopolistic tools is not the right of application developers.
Please talk to an actual lawyer before making legal claims, because to be blunt it's very clear you don't know what many of those terms mean in a legal context. VW is not a "monopoly". They have no obligation to allow the use of their software on platforms they don't want.
I do know what these terms mean in a legal context. I am claiming that play integrity is an anticompetitive and monopolistic tool, of which VW decided to use. I am not claiming VW is a monopoly. What you are claiming is their right to do, is not their right at all, and is illegal.