Thanks Emma, for sharing your thoughts.
Firstly, an idea to go for stealth, i.e., to buy those The Secret Step-By-Step Guides, which “magically” would do the work is nonsense.
From Seller Central: “ All Amazon sellers should be working towards achieving and maintaining a level of customer service that meets the following performance targets. Failure to meet these targets does not necessarily put your Seller Account in negative standing, but failure to improve may negatively affect your account.”
Emma, this just means that Amazon wants you constantly working on customer service, i.e., performance metrics. This is the only right answer to your question, why a seller account got suspended.