The online world has fallen in love with content management systems simply because they allow users to own and alter thier own website without the need to pay a developer. The costs are far less to purchase a theme plus half a dozen widgets and plugins than to have a developer spend hours designing and developing it from scratch.
CMS's can be used as a skeleton framework for some more in-depth projects but in many cases that just bloats the website causing other problems that can be avoided.
A well developed and designed bespoke website will perform far better than a CMS in the case of SEO and performance. A developer can far more easily produce better page loading speed results and search engine rankings than any CMS
The main complaint against CMS's is that they all look the same. That is not necessarily true but you can normally tell a bespoke website from a CMS simply beacuse the bespoke site can be made to look and function in ways the CMS cannot.
If you have any specialist requirements that you feel cannot be fulfilled with a CMS please contact us to discuss your requirements.