From publisher blurb:
Better Backgrounds is a book full of backgrounds that give you fun new things to spend your hit dice on. You could take the ordinary boring Soldier background from the PHB, which gives you two skill proficiencies and a bunch of other junk you'll never use, or you could take the Soldier background from this book, which gives you the same two skills, but also lets you spend hit dice on Battlemaster tactics or extra attacks. The noble background can spend hit dice as a reaction to mimic the Leadership ability that you see in NPC stat blocks sometimes, and a folk hero can permanently reduce their hit dice - but not their HP - for additional save proficiencies.
The book comes with twenty-one generic backgrounds suitable to almost any setting as well as twenty-five backgrounds specific to the Creative Commons Weskven setting, and while not all of the Weskven backgrounds will fit into your homebrew world, probably some of them will. The Drowned background refers to a specific cult of elemental water from Weskven, but you probably have a cult of elemental water in your setting, which means you can probably use the Drowned background, and so too with guild assassins, elven rangers, or those raised by goblin clans.
And the backgrounds advance with your level, as your past experiences and upbringing continue to inform your ongoing development as an adventurer, so while your background will never matter as much as your class, it will always remain relevant.