Also, if that were true, there wouldn't be a reason to ban Element or these other apps in the first place.
Reproducible builds, combined with Android's developer-signed binaries, means that you don't _need_ to be super-vigilant to detect backdoors. You can investigate binaries after the fact (especially since virtually every version of popular apps is archived on third-party apk sites), and see that the signed build is not reproducible and at that point you can very easily dig into the binary to see which changes were made.
Reproducible builds, combined with Android's developer-signed binaries, means that you don't _need_ to be super-vigilant to detect backdoors. You can investigate binaries after the fact (especially since virtually every version of popular apps is archived on third-party apk sites), and see that the signed build is not reproducible and at that point you can very easily dig into the binary to see which changes were made.