User-defined fields are well represented in user forms (radio, check boxes, etc.).
But unfortunately not taxonomies.
Is there a way that taxonyms can also be better represented?
Unfortunately there aren't any options to modify the HTML markup that is generated in the forms for the taxonomies.
If you wanted to change the appearance of the inputs for taxonomies you would need to study the generated markup in your browser console and add CSS to achieve the changes. If you needed to modify the markup itself rather than just applying CSS then you would need to use JS to alter the markup after the form had loaded.