What features should a premium wordpress theme on Themeforest have?



I have sold a couple of HTML5 games here on Envato, and I have a full time job as a Web Developer where most of the time I develop new dynamic, resonsive wordpress themes from scratch.
Usually we have a designer who makes a stunning PSD layout of the website and then I develop it on Wordpress and make it dynamic, responsive and all that stuff.

I have been thinking of developing premium wordpress themes for Envato but I am not
sure what features should a “Premium” wordpress theme have?
Lets take an example of this theme https://themeforest.net/item/bostan-business-business-theme/5030415?s_rank=2
Visually its a great theme with great layout, is responsive and customers seems to love it, judging from the reviews.
Now I am more concerned with what’s going on in the back at WP Admin, how much of content is dynamic and how much is static? What plugins he/she is using? whats the structure of its template parts/pages?

Like I said I know how to develop a wordpress theme from scratch, i just dont know what features should i incorporate into the theme for Envato to accept my theme in Themeforest.

If anyone who has been selling themes on themeforest can help me out, that would be great!
Thank you!