In business I am cut throat and I see this as an opportunity to migrate a huge percentage of googles (app store) customers to F-Droid.

In order for this to be possible F-Droid is going to have to spend the next 2 years campaigning against google as a more liberating alternative; which it already is. If the customers aren't all at the heels of google they should care and shift over. Android was not created by and is not a google product,, so they can't truly enforce the developer or side loading thing if a good percentage of the market gets an alternate non google android.

If I were F-Droid creating my own spin of android (basically stock with F-Droid bulit in) would be my main objective currently

I don't see the issue:

1. F-Droid compiles the apps
2. F-Droid publishes the apps
3. F-Droid gets registered
4. F-Droid subclasses app identifiers under its own

...and things go back to normal.

You won't be able to update an F-Droid app with an Obtainium one, but Android is already warning about those, not allowing automatic updates from mixed sources.

Some of my favorite apps are on F-Droid and nowhere else.

These apps are for the privacy-minded people, by privacy-minded people who will absolutely refuse to be tied by name (or digital signature with an identity verification process) to their apps.

And then there's the problem of making legally gray apps (emulators), now someone needs to be tied to that app, which makes then easier to find, or if an app starts to irritate a government or corporation, then they can find who published it pretty easily (likely without proper the proper legal oversight/subpoena) even outside of the Play Store.

What the fuck Google.

It's not closing down F-Droid, but rather not allowing to operate normally in stock Android. There are still alternative Android systems that makes use of F-Droid.

https://www.androidpolice.com/supreme-court-deals-google-a-blow-forces-major-play-store-overhaul/