Google themselves don't really follow material all that closely over their entire product line.

Android 6 was basically the peak of the UI, IMO, the icons were very consistent and nice early material.

In later versions they shrank the icons and stuffed them into circles and started using a horrible color scheme, then they killed blobmoji and started outright copying Apple's hideous emojis with that awful gradient and pseudo-skeumorphic visuals.