I have exactly that deal at MS (and I know many others who do), and I'm a couple levels away from DE.

I'm later in my career, don't need the job for $$ (they know it), lead a great team, work on a meaningful project that I pitched in an area where I'm an expert, great support from management. The only thing remotely close to "red tape and institutional slowness" is about making sure what we build meets the promises (privacy and compliance, for example) that we've made to customers.

As long as he doesn’t do anything that impacts the actual business. DEs working on Microsoft products absolutely have red tape and institutional slowness.

Not only that but he probably has a small legion of full time developers working on his projects now that no normal FIRE savings would be able to afford.