Also do many drones use GPS / dead-reckoning and follow pre-guided paths, to avoid need for comms.
Came across - https://www.youtube.com/watch?v=7fgcxDRti5s recently which uses an array of IMUs and filtering, to they claim get accuracy similar to a fibre optic gyro.
[1] https://www.newscientist.com/article/2415318-ukraine-will-sp...
a) Many drones still are being used for ISR (intelligence gathering). Live feed is valuable. Solving the navigation/guidance problem with dead reckoning doesn't let you solve the intelligence issue.
b) Turning FPV drones back into fire and forget munitions kinda robs them of their value proposition. We -already had- smart munitions that could be fired more or less unobserved into an area, and which could then more or less autonomously select and attack its own targets. FPV drones (in some applications) let you have part of that functionality (you can launch an attack into a general area without knowing precisely what you're aiming at, while still getting pretty precise terminal guidance) at substantially less cost (though granted the cost savings are coming from a variety of factors, not just the sensor portion).
I had this idea a few years ago when I was learning about VR position tracking issues stuff. Kinda surprised this wasn't a thing immediately after the first MEMS gyro honestly?