Android

I never implied it was, however if someone is using graphene as a way to achieve mobile security, it can generally be assumed they want said security if they switch to a different OS. Iodé and CalyxOS both support more than just pixels, and don't do data collection, nor do they sacrifice physical security. Mobile Linux on the other hand, has very little physical security, and very poor application sandboxing compared to the aforementioned android forks. It wouldn't make sense from a security perspective to skip over android forks directly to {postmarketos, Ubuntu touch, armbian/mobian, manjaro mobile...} unless your goal is to use a Linux phone without caring about physical security and app sandboxing (which would not make sense if you are using Graphene, and don't want to change your threat model too much while not supporting Google.)

I require my banking app to work.

Just get a flip phone for calls/SMS. Then pinephone for cool stuff.

As someone who only uses fedora on all my PCs and iodé on my phone, I'm not sure why you think I'd say this just to stir up drama. I've done the research into what would be available on mobile relative to my current threat model and found its not ready, and will most likely not be ready for a long time unless were somehow blessed with another Steam deck like moment for phones.

Also, can we stop the stupid spongebob chicken mocking text? It makes your response seem a lot more negative than it needed to be.

Everyone does run proprietary hardware with its own hardware vulnerabilities that could very easily be exploited and escalated without proper security. Unlocked bootloader leaves you open to very easy physical attacks. Phones batter is low and you need to charge it in a public space? You better hope no one had modified the charger with something like an RPI to silently exploit your phone. Crossing a border into a country and they suspect you're some sort of threat? There goes all your personal information directly to their government. Not running software that updates the hardware's proprietary software drivers? One text message and you've got a rootkit.

You are more than welcome to run less secure and/or insecure software. No one is telling you you can't. If someone is on GrapheneOS however, they're probably not using it to be on a less secure os. Most people don't want a less secure os. I'm glad you currently have the option to do what you want, but this response to someone using a secure OS about how to stay secure didn't really need an "um ackshually" about people who don't want a secure os.

I can't imagine someone who wants to use their phone wants to spend that time using it setting up sandboxing by hand.