We do not use any third party platforms or any website building tools in our development process.
There are three main components we always use.
Our CSS & JavaScript documents are called up from links with the CSS at the top and JavaScript at the bottom which is the only correct way for fast page load speeds.
Other systems mentioned produce CSS and JavaScript inline in the web page in no particular order which is not optimal for fast loading web pages.
Further to this website builders often have a plethora of templates that can be used and re-used meaning the possibility of someone else using the same one as you choose can be quite high.
All templates we make are individually designed and developed around our clients content.