No one can and people have been complaining about it for decades.
But there is no standard or standard body anywhere for terminal colors so there is no obvious way to improve this situation.
And no urgency either, because all terminal emulators allow users to customize the palette anyway.
There are fewer blue cones in the fovea centralis than there are in the surrounding parts of the macula, so humans can't resolve details as well in blue light.
If I was the maintainer of a terminal emulator, I would see a quite obvious way to improve the situation for my users: change the default colors so that dark blue is brighter.
There's no obvious way to unilaterally improve the situation across the whole ecosystem, that's true. But I don't understand why individual terminal emulator maintainers don't fix it for their users.