We have a development teen designing our website from almost one year. Now is down and they did a wonderful job. We are happy, except for EE2, witch is fine but we will prefer to upgrade up EE3 (we already upgrade the license year ago).
This is their answer to my question regarding way we are using EE2:
I can answer your EE3 question though as it's a relatively simple one to answer.
While EE3 is a stable enough platform, but there are a large number of addons that you are using which are not EE3 compatible or released yet. Expresso Store for EE3 still hasn't been released for example and a number of the other add one that you are using.
Just because EE2 will be end of life, but it's not going to stop your site operating and running. In fact, EE1 sites ran for many many years after EE1 stopped support.
As I explained when we first started the site - we don't have the luxury of EE3 because addons are not available to do what you need.