SPA is very broad. Static content work best when delivering only the minimal assets needed to render. Googles AMP does a very good job at this. Dynamic apps have a very different set of concerns. All SPAs aren't the same. Only the stateless, pure renders, like React and Vue, offer a compelling potential to unify the concerns of static content and apps that need to run across multiple platforms and network conditions. It comes at increased complexity and cost to maintain a multi-platform structure. If there's no business or consumer benefit there's not need to over engineer a solution to use a SPA.