Obsolescence of human workers/employees.

I haven’t looked into it (because Android repos are confusing), but I assume it allows just one specific signature to spoof one other specific signature. If so then I do not see such a security issue, because it wouldn’t suddenly open this mechanism up to everyone.

Even if it would require spoofing of multiple signatures, if there is a limited list of signatures to spoof as and a whitelist of signatures for the apps that are allowed to spoof them, then it would also be limited enough, IMO.

IIUC, you don’t need to patch LineageOS anymore for MicroG: https://github.com/lineageos4microg/android_vendor_partner_gms/blob/master/README.md#microg-mobile-services

Maybe an unpopular opinion here, the Android security model is based around trusting the vendor of the device or ROM more than the end-user, which I find wrong in principle. The origin of trust needs to be fully in the hands of the owner of the device. Otherwise you take away the self-determination of the users, and that should never be an option when it comes to security.

Users themselves should be able to give or take away trust however they choose, and if they are unsure on whom to trust for certain things, they should be able to delegate that trust-management to a third-party on their own accord and with the ability to revoke it at any point.

Everyone is different, and trusts entities to different degrees. For instance I would trust MicroG more to only transmit data that is absolutely required to google servers, than the gapps.

Also, modifying the kernel is already done by google, in order to provide hardware support, so patching it additionally doesn’t automatically make it more or less secure. That depends on what those patches do, and if those patches are properly maintained.