There are several reasons for the separation of the bridge and engine room. As already written, it is about the visual beam from the bridge. The otherwise necessary reduction of container layers on deck is not necessary. This made the very high container capacities possible. With a conventional design of the same size, the limit would be around 18,000 TEU.

The engine room, which is located far aft, allows a short shaft tunnel. By contrast, the EMMA MAERSK class (https://www.shipspotting.com/photos/big/5/4/2/2432245.jpg?cb=0), ships of the same length with a combination deckhouse/engine room, have shaft tunnels 120 m long. This is not only technically complex, but also takes up space that reduces container capacity.

Since fuel may no longer be stored in the double bottom, the tanks are located underneath the bridge/accommodation. These tanks would otherwise have to be installed in the hold area.

And as already mentioned, the two closed deck areas increase the stability of the ships.
Hope my short description helps.
Regards

There are IMO rules who dictate the Bridge navigation visibility, also If you put the bridge also aft you loose a lot of capacity due to reduced height of containe rstacks fwd.

The separation of the machinery and bridge/forward accommodations, why is this? I assume it is partially to do with size and visibility, but don't actually know.