The notion of "adoption" of successors enables a kind of richer meaning of inheritance.
For example, in Japan it's common for an owner of a business who doesn't have a suitable successor who is genetically related to them to literally adopt the person they want to run the business.
This seems like a kind of random semantic trick to just pass on the company in a normal way, but I'm not so sure.
If there were just a normal business transaction, it would be beholden to the precise requirements of the contract.
But a literal adoption implies a rich, multi-layered meaning and responsibility.
You literally become legally obligated to your "parents".
Similar on paper to selling a business, but different in ways that matter
Ensuring long-term commitment to a mission is a challenging problem to solve socially, but this helps.
It also allows the business owner to not simply pass it on to a family member, but choose the person they think is best suited to do the mission.
Rome's golden age was when, by happenstance, there were five generations of emperors who didn't have suitable heirs and thus had to adopt an heir.