How about an app that opens an SQLite DB so that strings and numbers can easily be edited, and then on file save, SQLite's internal pointers and markers are updated ? Maybe an Emacs mode ?

There is a definite demand for some import format that you can trivially edit - CSV excels at this right now and JSON isn't that bad. Binary dump formats definitely do have a time and a place but there is also a separate need for trivially human readable formats.

I can - and do - read a CSV by opening it in Notepad++ to view basic data. This isn't possible with a SQLite file.

In some incredibly pedantic sense, sure. But the difference is that every computer comes with what a human needs to read a CSV file. That's not true of an SQLite database.

Could it be?

Sure, could be. In about the same sense that it could be that every computer comes with a free and open source operating system. Could be; it's not theoretically impossible -- but...

So what's the alternative? Good old pen and paper?

Doesn't count, you still need light to make it human-readable.

/s