"...but it's too full of functionality! "
The advantages of using a framework like Mojo is that you get all the benefits they bring, but nobody forces you to use each and every feature. Your application code is separate from the base framework, so caring about things which won't impact you (should you choose not to use them) seems illogical. Writing a safe CGI and DBI "from scratch" seems fraught with risk for little reward compared to something like Mojo/CGI & DBI, which all have literal years of developer time spent honing the solutions.