I verbally exclaimed WTF the first time I saw that. How did anyone think that ridiculous distraction is an improvement? Doubly so when the name of the file you want to open next is in the current one --- and helpfully covered up by that abomination.

It's hostile to users like us that can deal with a lot of data at the same time. But many people when they see "old style" UIs get overwhelmed by the mass of information and data, and having that information subdivided helps people. Sadly, they are the majority and we are the minority, so UIs get designed for them and not for us. Nowadays computing systems are being used by the 99% so they are also designed for the 99%.