Is getting f-droid on iOS even possible I know it’s not right now but if work was put into it would it be possible? Obviously this wouldn’t be able to work without a jailbreak which isn’t hard these days especially with checkm8 exploit and various other jailbreaks.
No, this will never be possible and is completely superfluous. F Droid is an alternative to the Google Play Store for free software android apps. Those apps are for android specifically, and any that might be cross platform and happen to work or have a version for iOS should distribute those versions either through the app store or some jail break alternative.
The fact is that if you care about free software then Apple is one of the worst options for compatibility.