Ruby on Rails: Is there any specific reason why the default error page extension not html.erb?

so I have a ruby on rails application, and I want to change the default error page, for example the 404 error page. But the 404 file extension is html, not html.erb, and all the assets like bootstrap is not loaded. It's too much work to manually write the css to style it and make it responsive.

So is it alright if I change the extension to html.erb and load all the assets like in the application.html.erb. Is this good? Or is there a special reason as to why the assets is not loaded and the extension is html ? vulnerability maybe?

    <%= csrf_meta_tags %>

    <%= stylesheet_link_tag    'application', media: 'all', 'data-turbolinks-track': 'reload' %>
    <%= javascript_include_tag 'application', 'data-turbolinks-track': 'reload' %>

Thanks in advance!