It can be done with some custom code.
But there is no issue with additional plugins if you carefully select the ones you require. This is the WordPress way.
In this instance that plugin performs a single function, which is your requirement aka FAQ Accordion, so there should be no negatives for using this. You simply want to avoid adding plugins that are ‘bloated’ ie. they add LOTS of features, functions, addons when all you require is a simple single function.