I use premium good themes from templatemonster. They have professional design, many skins, plugins, good support and documentation. This is all i need, for good work. For example you can read the review about my favorite themes Divi and Monstroid on https://www.templatemonster.com/blog/divi-3-vs-monstroid2-th... this article also has comments from people who used this themes.
For me Wordpress is the best. This CMS very customizable, has a lots of plugin for adding more function, it is important properties. Also it has a large collection of themes, that makes your work faster. I often use them. My favorite are Divi, Avada and Monstroid. They all coded by Templatemonster. Here is a review about Divi and Monstroid "Divi 3 VS Monstroid 2: The Great Showdown" - https://www.templatemonster.com/blog/divi-3-vs-monstroid2-th... you can read the descriptions and comments from users.
WordPress is very good and popular CMS. It has a large collection of templates that can help developers to design the application in a very short period of time. I often use them. My favorite template is Enfold - https://www.templatemonster.com/blog/monstroid-2-vs-enfold/ it has 25 child themes, with their help, you can build a website for any niche.
Professionals and experts is always use WordPress development services for making a responsive website because it is easy to handle and increase business growth day by day. It is cost effective. Today, many websites and blogs is making on WordPress. Also there are many templates, that make your work faster. I usually use premium templates from templatemonster. My last work was with theme Enfold - https://www.templatemonster.com/blog/monstroid-2-vs-enfold/ very good quality.
Professionals use WordPress because it is the best and popular CMS. It is user friendly and highly customizable to use. Also it has a large collection of templates that can help developers to design the application in a very short period of time. That's why more than 27% of the web is powered by WordPress. I created many sites on WP to. Now I want to use some new premium theme for me, it is X Theme - https://www.templatemonster.com/blog/x-theme-vs-monstroid-2-... here is the description. I think i will create professional website very fast with this template.
It's good instruction. I'm now start my new site on Wordpress, this is the best CMS i think! I use premium theme X theme, it have over 20+ premium plugins along with your theme to get you started. Here is a review - https://www.templatemonster.com/blog/x-theme-vs-monstroid-2-... about it, in comparison with another theme Monstroid, very interesting.