Did you read the article? I think your questions/complaints are answered there.

Tldr; the new map solves some distortions (to the tune of 14x) but also there’s a human element to this. It seems like an obvious and overdue improvement.

Retaining an inferior map because they won’t be used for navigation is an odd defence.

They literally say that too.

In February, the AU's 54 member states adopted it, and said it "more accurately represents the sizes of all continents, particularly Africa".