It's been discussed before and @tessus is maintaining a thread about it: List of CSS elements which should have a class
If you want to create a pull request, I think it would make sense to show what you have in mind first by modifying just one or two files.
Also styled-component is not the issue here because before we'd just set the style directly on the element so there weren't class names either. But isn't it possible to get styled-component to use a non-random class name? I seem to remember it's possible to get it to convert for example <StyledEmailInput> to <div class="email-input"/> which would be ideal.