In my understanding, it's not the OS that makes it a toy but the hardware. I guess something with open schematics (Librem 5, Pinephone) should be better, or an open-hardware device like Precursor.
replyIf the open hardware offers at least comparable security then maybe. If the hardware is an open book then no.
replyA short list of the hardware security measures necessary to consider it "not a toy" ;) -- https://grapheneos.org/faq#future-devices
I'm not convinced that all of these is required for security. My Qubes OS desktop is probably more secure than any GrapheneOS phone, and it only requires good hardware virtualization for that.
reply> If the hardware is an open book then no.
So you choose security through obscurity. I have no further questions.