MVC was a hack of a pattern that developers adopted to get server side rendering architectures to even work. Good developers recognized its many flaws and when front-end development became decoupled from the server, tried and true practices and patterns such as modularity, reusability, and separation of concerns were adopted to the front end and the results of those efforts are the front end frameworks and libraries we have today. They are not variations of MVC. If you work with them as such, your SPA architecture will look just as brittle and shitty as a server-side architecture.