We can remove the image via layout in our custom theme. For example, in our custom theme:
app/design/frontend/Vendor/Theme/Magento_Catalog/layout/catalog_category_view.xml
<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" layout="2columns-left" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<body>
<referenceBlock name="category.image" remove="true"/>
</body>
</page>