it is around 20% of the world sites are run using Wordpress (as George says), from simple blogs like you mention to some of the worlds biggest sites.
Wordpress does have its very good features some great plugins like Yoast, which helps to improve your site from an google presepective - changing meta deta, titles etc.
I do use wordpress for my sites for one reason only - I can't code and wouldn't know where to start.
If you are a competent coder and by the sounds of it you are - I would stay away from WP, for all its great benefits and there are loads, its still an out of the box solution that is trying to meet everybodys needs so is not brilliant and while you can do some wonderful themes etc in wordpress you are still working within their framework.
Starting from scratch (if you have the skills and the time) is always a much better solution. So much more can be done