Your information is only as secure as who you share it with.
Here are a couple of other things to keep in mind: most activists you'd want to protect can't afford pixels, at least not on the scale that you'd need. Many journalists aren't that good with cybersecurity.
Want to get higher adoption ? Help the project work towards even lower friction. Pester Google and the banks to allow tap to pay and stuff you get from less secure phones to just work. Help write more great step by step guides.
In a pliers to the fingers threat model, which is what you're dealing with in many cases, plausible deniability and things like being able to wipe a device with a pin number matter more than a perfect 0 day protection.
GrapheneOS ships with sane defaults. One thing that maybe would be nice is a way to not have a logo on the splash screen, and what'd be even better is if Google could do the responsible thing and allow Graphene to not have the "different OS" warning bootloader.
In other words, calls for grand gestures are performative, security theater, and a distraction. Supporting the project, financially if you can, or through grunt work, by doing things like finding ways to hound the powers that be to do the right thing if you can't afford to donate are much more useful if you want to achieve more than feeling good about yourself.