What is the difference between "benefited" and "was benefited"?

The verb benefit is both transitive and intransitive.

The company was benefited from xxx.

The verb benefit has been used here as a transitive verb in the passive, but this sentence is not grammatical. You should use "by", not "from", before the agent xxx in the passive voice as follows:

The company was benefited by xxx.

In the active voice, it is as follows:

Xxx benefited the company.

You usually use the benefit in the active voice; its use in the passive is not so common.

The other sentence:

The company benefited from xxx.

It's grammatical, in which the benefit has been used as an intransitive verb.

There are two different verbs "benefit."

There is a transitive verb "benefit" meaning to provide a benefit.

His education benefited him financially.

Because it is a transitive verb, it can be placed into passive form:

He was financially benefited by his education.

There is an intransitive verb "benefit from" meaning to receive a benefit.

He benefited financially from his education.

That cannot be turned into a passive.

His education was benefited financially.

is obvious nonsense.

So,

He was benefited financially from his inheritance.

is a subtle, minor error in grammar.

Benefit as a verb means to be helped by something or to help someone. For example: - I have benefited greatly from her help. - The new law will benefit many people.

• The main difference between (The company was benefited from ...) and (The company benefited from ...) is simply that the first sentence is in the Passive Voice form by which the speaker can hide the identity of the actor (the subject) for some reasons and the second is in the Active Voice by which the actor is revealed as in the above sentences (her help and The new law).

You cannot place 'benefit l' in the passive voice. The second part is correct.