Hi there,
That really depends on if you are comfortable with lots of custom coding or not.
I think it should be possible with Hooks Elements and lots of Author related if conditions:
https://docs.generatepress.com/article/hooks-element-overview/
https://codex.wordpress.org/Conditional_Tags#An_Author_Page
But then of course you will have to style them etc with CSS.
I would still recommend going with the plugin route if you aren’t too comfortable with codes. Plugins are also just codes so if you find a well coded plugin then it shouldn’t slow your site down.
Let me know if this helps 🙂