Pretty asked question @DevKumar
WordPress themes should be contains the following features and conveniences.
- Theme should be fast and comes with light weight coding.
- Theme should be Mobile friendly.
- Theme should be SEO friendly like 404 Page availability etc.
- Themes contains useful widgets such as post sharing buttons, related articles boxes, subscription box etc.
Personally I would recommend you to try Genesis framework and their child themes,which relevant with your web category. Hopefully, it will be proven best for you.