Upload multiple Standolane Media Entities (Images) without Reference Field
The Media Bulk Upload module will allow you to upload many images at once.

This is the Drupal 8 module to bulk upload files and create the media
entities automatically for them. It uses DropzoneJS
to quickly upload multiple files.

The bulk uploader will allow you to edit fields on the media item before saving. You'll want to set alt text for each image, and your Taxonomy Term reference.