Doubts on scratch MVC or any MVC framework?

I have seen many PHP MVC tutorials videos in youtube out there. They are telling those are to understand the MVC pattern and do not use it for your real project. :thinking:

So i having doubt that,
is it much difficult to do big shopping website from scratch MVC?
is the MVC concept is to just understand the pattern?
which is to use scratch MVC or any MVC framework for small or big website?

I guess as the as project grows on the scratch MVC may produce many bugs from scratch works.

Are people using scratch MVC or any MVC framework for small or big website?

please guide me.