@frederik said:
Not sure I get you here... 
A plugin for WordPress isn't something special like a plugin for a browser...
Do you have any knowledge about WordPress...?
Yes, I develop websites using it and know a lot about how it works under the hood.
@frederik said:
A plugin simply makes it easier for the average Joe to embed content on his/her website...
Most people are unable to make even simple web-code, thus a CMS is required...
Please remember that WordPress isn't just a blog-tool... It was, but today it's nothing less than the most widely used CMS in the world...
The problem is not WP or WP plugins. The problem is that browsers handle text and images using HTML, however to deliver interactive graphics they need some help - to date this has come from a "low-level" plugin that extends the functions of your browser. Adobe Flash is a common plugin of this type. Unity player is another example. LightUp WebPlayer is another example of a plugin that extends the functions of your web browser - in this case it adds functions to draw realtime 3D .luca files and know what to do when you drag and drop a .luca file on your browser.
However, there has been a push to ban all these plugins and require using HTML5 / WebGL. While that might be a glorious plan in Google HQ, but as Pixero points out, the reality is that not all browsers support it. So deploying interactive 3D that works everywhere is currently not possible using 1 solution.
WP plugins are something much lighter and just some templates that make it simple to insert content into your WP webpages that would otherwise involve cutting and pasting HTML.
So having a WP plugin does not solve the problem. 