Keep in mind that only the Berserker is free. The other must be unlocked with a purchase from the Marketplace (see Player's Handbook, Xanathar's Guide).
Why can't the others be free as well? Core rulebook should all be included.
If by the 'core rulebook, you're referring to the Player's Handbook, it'd be because that isn't free either.
The Basic Rules/System Reference Document are free and contain a single primal path for the barbarian class (they contain a single subclass for each free class).
D&D Beyond offers for free what Wizards of the Coast offers for free, and charges for what Wizards of the Coast charges for
Here: https://www.dndbeyond.com/characters/classes/barbarian
Keep in mind that only the Berserker is free. The other must be unlocked with a purchase from the Marketplace (see Player's Handbook, Xanathar's Guide).
Why can't the others be free as well? Core rulebook should all be included.
If by the 'core rulebook, you're referring to the Player's Handbook, it'd be because that isn't free either.
The Basic Rules/System Reference Document are free and contain a single primal path for the barbarian class (they contain a single subclass for each free class).
D&D Beyond offers for free what Wizards of the Coast offers for free, and charges for what Wizards of the Coast charges for
Find my D&D Beyond articles here