I'm not saying the old Pinebook wasn't bad, I've never owned it but some of your points are a bit hollow for me.
> CPU was compared to the PS3 and GPU was compared to the original Xbox, for reference.
Why is this a problem? This is "desktop" hardware against mobile hardware.
> It barely ran with the stock software
How so? It didn't perform well? It didn't boot at all?
> and was unable to play a 480p YouTube video fullscreen without noticeable frame drops
With which software? Did it support the A64's hardware decoder?
> They were also unable to get Windows running on it when they tried using a Raspberry Pi image
...Is expected that you're able to boot Raspberry Pi images on completely different devices?
> Pine64 themselves claim that the machine is not a daily driver.
I think you should have opened with that.
> I had been looking at the phone a few days before and was astonished at how outdated the hardware was, even for an open source device that is possibly upgradeable.
Open source hardware projects don't have the luxuries that multi-billion dollar behemoths like Samsung do. They don't have access to pre-production SoCs so they're handicapped from the start and they need to handle everything from design to parts sourcing to manufacture to distribution themselves, with a small team.
That means you're going to get "outdated" hardware. You don't buy open source for the latest shiny things, you buy it for other reasons.