Why is having a Guru considered so important for removing ignorance?

Chapter 50 emphasizes that a Guru is essential because ignorance manifests from doubt, and this doubt cannot be removed without a Guru's guidance. The text illustrates this point by mentioning that even a supreme knower like Shuka suffered loss due to doubt (vikalpa). When doubt enters knowledge, it can make even a wise person prideful, ruining their understanding like a drop of fermented gruel spoils a pot of milk. Therefore, the text suggests one must first understand and remove ignorance with a Guru's help to purify the mind, which then allows for infinite knowledge and non-dual Samadhi to be attained.