The problem is not the conjunctive adverb therefore; it is the use of the word being in a participle clause. When you use the form "being + adjective" at the beginning of a participle clause, it is used to replace because/since/as.
Any contribution cannot be erased from the mind, therefore being essential for being successful.
Any contribution cannot be erased from the mind, therefore because it is essential for being successful.
Any contribution cannot be erased from the mind, therefore as it is essential for being successful.
Any contribution cannot be erased from the mind, therefore since it is essential for being successful.
Do you see how therefore collides with the because/as/since wording? Now try it without the word "therefore".
Any contribution cannot be erased from the mind, because it is essential for being successful.
We should remove the comma in this version, but use the being form and it becomes correct:
Any contribution cannot be erased from the mind, being essential for being successful.
Using being twice in the same clause is wordy and awkward. It might be better as:
Any contribution cannot be erased from the mind, being essential for success.
If you want to convey the sense of the continuous tense instead, there are many ways to do that. For example:
Any contribution cannot be erased from the mind, being essential for lasting success.