Is it difficult to upgrade Opencart from version 2 to version 3?

Question

opencart

There is an already created online store (about 500 positions) on Opencart 2 version. Will it be problematic to update the engine to version 3?

Answer 1

What does it mean to update? These are essentially different systems out of the box, i.e. there is no such hat as in WP, I pressed the button and everything was updated)), well, or in words it was updated.
There is nothing complicated. Just need to do:
1. Import/export of goods.
2. Re-upload modules (some may not be for version 3x), therefore, look for an analogue or finish it.
3. Fill in the template of your store (these are the styles of js fonts, etc. D).
4. Well, on the little things ...
THE MAIN QUESTION: WHY?