Addenda to @Douwe’s answer: any Android vendor needs to certify their OSes with the Google CTS to use Google Mobile Services (this is sadly a necessity to be usable for the average user). Android 7+ on the MSM8974 chipset the FP2 uses doesn’t pass the technical minimum requirements (Vulkan support and hardware encryption keys storage).
There’s more info on how the industry works, what are their limits and how Fairphone has fight the status quo in this old but instructive and #epic thread: