First thing to talk about is characters , I personally like this series because the characters are very relatable and face issues that happen in the "real world". Some characters are relatable because they are in middle school and others may not be relatable because they're younger or adults. I also like the characters because even though they may be simple, their decisions are complex and can sometimes lead you to want to change what they did. I personally think I can relate to Greg the most because he's in his last year of middle school just hoping it would go buy quickly but barriers literally slow the year down.
Another thing I can relate to that I already spoke about are barriers in the characters life's , characters face barriers that are relatable and frustrating that can sometimes make you think "I guess i'm not the only one that feels this way." For example: I noticed how Greg's mom is a barrier when he wants to play games on the computer but she wants him to get sunlight and when Greg's outside to long she wants him to be indoors. This type of barrier to me seems like Greg not having freedom and I think when Greg has less freedom he doesn't enjoy things.
All in all these fun, break books might be below grade level but they still have nice plot and a way to show relationship. Books like this could help you adjust your actions or see how to solve issues like a guide.