In Somalia, locals will not make the effort to fix the problem of colonial-era boundary drawing:
A border dispute in northern Somalia has gotten violent again. Since the 1990s the two statelets that comprise northern Somalia, Puntland and Somaliland, have been squabbling, and sometimes shooting, over possession of the Sool region that lies astride their border. Both sides claim it, and both are willing to fight for it. The dispute has been going on since Puntland was formed in 1998. Back then Puntland declared they controlled the Sool because the inhabitants belonged to a Puntland tribe. Somaliland based their claim on borders drawn by the colonial governments of Italy and Britain a century ago. Years of negotiations have not settled anything. Recently both statelets sent additional troops to the border in anticipation of a fight for Sool. Meanwhile, both statelets have been coming apart because of internal problems.
Look, what lines on maps aren't artificial, to some degree? And even if the lines match ethnic, religious, racial, and tribal extent, people blend and even move, making any line on a map obsolete in some cases.
Yes, there are some logical lines like mountain ranges (but ask India and China if you can't have problems there) and rivers (ask Iran and Iraq about drawing the lines in that case. Middle of the river? Far bank? Thalweg principle?).
But even in Europe, the lines have mostly settled down as the result of a bloody history that moved lines and people to finally--for the most part--coincide. But mostly they just stopped fighting to move those lines and ethnically cleanse where lines could not be moved.
Poorly drawn lines can certainly add to problems. Or make problems more intense. But a lot of other problems being solved could make mere lines a small matter.
Or are you really going to say that Somalia's largest problem is where long-dead colonial officials drew their lines?
Which is certainly a reason why the African Union is against revising those lines on the map. If they would stop blaming the old lines for their problems even as they recognize the death and misery that would flow from changing them, they'd all be better off.