If you fired a bullet at 450m/s at a FreeBSD machine sitting 50 feet away, it would have enough time to boot up and perform operations before being struck and destroyed by the bullet.
For many simple embedded systems that plug into the wall, the "boot" process will happen in under a millisecond. But it will take considerably longer than that for the voltage levels to stabilize.
The real thing which differentiates these from a PC or phone is that they are not running what we would typically call an OS. They may be running an RTOS (a very simplified OS), but for many of them, as soon as they have stable power, they are off to the races (Just like the home-computers of the 80s. Just plug in and go.)
Of course the definition of "usable" work can be argued over but even a C64 released in the 80s will run your code in less then 10us
1ms is an enormous amount of time. I'm really curious why you would think otherwise
Like I said link a microcontroller that can meet that. 'Usable work' can be as little as adding two half-precision floating point numbers together, and sending it can be any possible method.
https://www.youtube.com/watch?v=FYdAT0v4DHs (Scott Manley)
450 m/s is 1620 km/h