How to create a WordPress theme for themeforest?

Question

themeforest

Hello!
I am a web designer and 2 conditional years ago I decided to test my skills in writing code. In principle, I liked writing code and slowly I switched to Wordpress.
Initially, I didn’t even think about creating my own theme, but suddenly it became interesting to make a theme for the themeforest site myself.
Many focus on the highlight of the design, but for some reason no one answers the question of how exactly the Wordpress Template is created. Yes, I can pull the layout. But what's next? How several versions of the main page, header, footer are made. Is it mandatory to use builders like elementor, deprecated unyson, WPBakery Page Builder? If done under elementor do you need pro.
If it is done without builders, how several variants of certain objects are made.
Thanks to you in advance. I understand that such questions are not entirely correct, but still I hope that at least 1/1000 will understand the essence of the issue

Answer 1

If you have knowledge on how to stretch the layout without using unnecessary unnecessary plugins, except for ACF, probably ... then to extend the theme's functions, you should probably look towards the Redux Framework
. Personally, I am against using any page builders, because they clutter up the code too much, and pull half of the Internet along, until you get to the desired image in the code, you need to open 100 divs
But if the theme is for an ordinary user who does everything only through the "graphical" interface, then yes .. normal