Eliminate render-blocking resources
This is not a Helix problem but the Joomla problem and any other CMS. Helix simply uses the Joomla API requirements to include scripts in HEAD. Therefore, you can only use special extensions to solve the problem. For example, JCH Optimize.
Consider such a moment - if you use a framework-template, you will always lose in speed compared to a clean template. This is a fee for the lack of knowledge and the ability to edit through the interface instead of coding.
When you encode, you only connect the necessary things. But the framework template has a lot of things for all occasions, for the convenience of the user. Therefore, the stack of scripts and styles located in Head is always very large. Even if you do not use it.