[shiroiuma]

But what improvement does Debian really need, beyond the capabilities it already has?

Linux in general could use various improvements, if some billionaire decided to fund people to work on it. But I don't really see how any distro could use the lion's share of that funding. Instead, much of it probably needs to go to infrastructure things like drivers, Wayland, etc., so that Linux works better on people's computers. Other things that could use development funding are various applications. But these are things that all distros share.