Why go vanilla? Because it's less complex, often smaller over the wire, nearly SEO ready, etc. Of course if you can anticipate needing a lot of interactivity which cannot wait for separate page loads then consider the FE frameworks. Maybe even go hybrid if only one or two pages need app-like components.

Right tool for the job is hard to know before you've done a similar job, so I can relate to wanting to start with the most robust hammer.