I understand that there are many good reason to use paid database engine, such as greater reliability.
However, that's exactly what the question ask. Also, the idea that mysql innodb is not reliable is not something most people are aware of.
Anyway, is the question prohibited due to the answer being too obvious? Off topic, or what?
If you pay because you got things in return like support, stability, predictability, maintenance, built-in security and other out-of-the-box features, why not turn them into an answer? Why downvote the question?
For example, a person can explain what features oracle has that innodb doesn't.