Where to use js frameworks?

Question

Angular

Hello! I started studying vue.js (not the essence of which particular framework in this context), I watch the lessons on YouTube, looked into the documentation. In general, one and the main question remained - where to use it? I already know roughly what it can do, it remains to be understood - in what cases to use it? The registration window is ok. There lists - okay. But this is somehow not enough.
Here are two examples - I have a regular one-page landing page. Where might he be needed?
The second example is an online store with a main page, a product category page, a shopping cart page, and a product page.
What considerations should be when it is clear that a js framework is needed here?
What page elements need it?
ps perhaps a nerdy question, but the technology for me breaks the presentation of the web a bit after "implement and put on wordpress". I want to form an understanding of the place of js frameworks. General infa lifted the veil, but not completely

Answer 1

SPA is their main purpose.

Answer 2

• Admin panels - here frameworks are kings
  1 backend with server API
  3 applications (web + android + iphone)
  Very convenient structure and well supported -- no matter what API and on what tool it was created... the frontend knows nothing about it, it works with naked API, as parvilo higher expertise - frontenders do a good frontend, backenders - a good backend, and you don’t need to intertwine in pose 69 (although they are still intertwined, but this is about something else :)
  Even if attachments are not needed, there is still low dependence on the creation method back end - change frameworks, change languages ​​in general (to Dzhanga, to Rails, to ASP.NET) it doesn't matter at all ... the main thing is that the API is necessary for the front.
  For landing pages - do it, why not, if you master it well and development will be cheaper than on JQuery

Answer 3

Have a look at the laravel spark module.
This is an option how to use not in the spa