Eberron (Rising from the Last War) is a historical landmark for Dungeons and Dragons. It is a sourcebook that has several distinctions no other 5E sourcebook has.
The Artificer is the only Non-PHB Class to ever officially be released for DND 5E \ This is almost certainly because a new Class has the possibility of upsetting game balance (a significant risk from a TTRPG Design Perspective)
It is the only 5E sourcebook that has ever had the name of an official DND World in the title
Every 5E sourcebook (except Ravnica, which is a MTG Hybrid) has been an adventure with flourishes from one or more DND Worlds \ This 5E sourcebook is the closest Hasbro has come to creating a Setting Book (a detailed World with an adventure flourish) as has been presented in every other version of DND
The Group Patron, a major new mechanical element in this 5E sourcebook, may be evidence that John Harper’s “Blades In the Dark” will impact rules design for DND 6E
Dragonmarks are the most innovative elements from Keith Baker’s presentation of Eberron in 2004, when he defeated 11,000 competitors (including me) to win the DND 3E World Competition (a historic event that is isolated to DND 3E, and no other edition of DND)
For me, Eberron (Rising from the Last War) gives hope that Hasbro may actually release a Setting Book for DND 5E.