I'm a Joomla! founder and I won't ever say it is the best, and anyone who claims Drupal/Wordpress/Whatever is "best" would be talking out of their backside.
Forget about the tech - *WHO* is going to be publishing content for this website? The reason there are so many CMS offerings is because there are so many different mindsets and working styles of content publishers (and so many different coders who program without bothering to ask people what they want). Please please please don't pick the tool based on a techie's input! Ask the humans that are responsible for managing and providing content for the website.
For example: My default choice is Hugo (http://gohugo.io/), fantastic for simple sites that are all about content (and not dynamic doodads and whoo-hah of dubious value). Essentially blogging with a static server, relegating scale, cost and security to relatively low-impact issues. If you want a WYSIWYG environment and lots of gizmos, or are not into writing markdown then this is absolutely not the setup for you.
Pick the tool based on who is maintaining the website/content. The tech under the hood is generally irrelevant, it's about the content, silly!