Memes are not really a solution to Malthus's dilemma. They are just a different type of substrate for inheritance. The world filling with memes might indeed prevent the world from filling up with DNA - but then you have the exact same Malthusian problem all over again with the new medium of inheritance.

But memes are not morally relevant entities. Who cares if they suffer from the Malthusian problem, as long as human beings can have a high standard of living? (I'm assuming a non-upload scenario here, in case there's any confusion about that.)

The standard of living for those that remain could be high, though.

Yes, that was the point.