I remember when astronomers started using lasers for distortion canceling. A buddy of mine had been working on spy sats for a decade and said the government was using the same technology (though in the other direction) when he arrived.
Hubble was built on a spy satellite bus.
Military gets the shiny toys first the reason why we have such great gyro sensors today in phones is because solid state sensors were first developed for guided missiles.
MEMS gyros are used in military INSs today can’t say if in missiles but in guided mortar shells and field artillery for sure.
You can’t strap a 150,000 INS on every shell you can’t even strap a 30,000 FOG INS on a shell.
Basically since we now want INS and GPS on every bloody field equipment and anything above a 20mm grenade should be guided muinitions you have to make some compromises. And MEMS aren’t that bad yes they drift but for their usecases the drift is negligible.
MEMS operate on vibration which can be induced with solid state ultrasonics.
Also since most navigation systems today are hybrid drift isn’t much of an issue over long distances anymore and for short distance applications it doesn’t matter.
MEMS are much smaller, FOGS can also be made smaller especially considering you can use a single external laser injector to feed multiple sensors.
So while RLGS are still probably the most accurate production gyro we can make there are technical issues on making them smaller and since we have alternatives there isn’t likely much reason to invest in miniturizing them further if it’s even possible.
This is at least my educated guess.