I don't want to do any review of the books because that way, it would be considered as my own personal opinion. the only way to figure out if the book is good or bad is to read it.
For a weak interruption appearing mid-sentence, we either place a bracketing comma pair to separate it or do not place any comma at all.
With just the lone comma, as in the example, the interruption could be interpreted as the clause after it.
The interruption here is that way and I suggest a comma pair for it.
I don't want to do any review of the books because[,] that way, it would be considered as my opinion. [T]he only way to figure out if the book is good is to read it.
Redundant words own personal and or bad have been omitted. To reduce wordiness, we could further omit that weak interruption.