Pixel 4 smartphone has a very advanced hardware.
In order to beat competitors Google used its capabilities in Advanced Research Team to come up with some new tech.
For 5 years they researched under PROJECT SOLI,
In simpler terms they explored the capabilities that can be achieved using RADAR tech.
RADAR sensors are less power hungry and can easily sense motion.
For this Pixel 4 used 60Ghz mm wave frequency band. The permission for which was not granted by Indian Govt. Well not only India but Japan Australia Mexico and New Zealand also did not permit the use of this wave length.
It appears as if Google is currently not prepared to launch these phones without these capabilities else they might have launched lesser capable Smartphone although that might have meant not a great traction among the masses.
So we will have to wait and watch whether Google comes up with new hardware , less capable hardware or is capable of convincing the Govts across world to allow it hardware.
Good new, other products showcased in Google Launch Event like PixelBuds, Nest Mini , pixel book etc shall be available in India.
So cheer up.