WordPress is an open source website management and building tool. Open source means that it wasn’t just made by a specific group of developers, it can be added to by anyone who has a good idea and knows how to build it. That’s partly what’s great about WordPress, because it’s constantly evolving with new and better features.
WordPress is unique with it’s wealth of plugins to choose from, all built to help make your website look better or be more functional. To understand the scale of customisation with WordPress, as of November 2019, there were over 55,000 plugins available for users. The most popular plugins help with SEO, analytics, selling (ecommerce) and page speed, with new and better plugins being developed daily. This makes WordPress a great place to build a website, not only will your website look great today and in the future, but it doesn't cost any extra on top of hosting.
The above being said, Wordpress can be slightly confusing if you're not familiar with the process of building a website yourself. You can find yourself somewhat overwhelmed with the options and tools, it's certainly a lot more confusing than a drag and drop website builder, due to the fact that it's WYSIWYG based (what you see is what you get). Your changes can't necessarily be seen in real time, making it slower to work and progress with.
Unlike other types of website building software, WordPress’ theme mostly come at a fee, certainly if you want a good looking, original design you should expect to pay. If you opt for a free template, it can be quite obvious that you have held back on expenses whilst building the site, painting it in a worse light, especially if you stick with the default options.
If you are computing inclined, you can edit the HTML of the website you are building, which allows for impressive customizability, if you know what you are doing!. WordPress is special in this aspect because on the majority of other website building services, it isn't possible to edit the root code of the website, which is sometimes a vital feature for the more serious webmasters.