I don't disagree with your claims, it's just not what I chose to do. One of the reasons I went with a different ROM was to discover the limitations and compromises that come with it. I have put #GrapheneOS on four different devices without issue over the past 2-3 years. So far I'm fine with the tradeoffs.
I have considered adding a low-end OEM device for experimentation in the BTC/Lightning arena. Having a dedicated test bed is a good approach. I used an old Pixel 3 without SIM card for my first GrapheneOS test bed. So I may do that in the future.