Plenty of SEOs recommend optimizing alt texts for your images to make your website more search engine friendly. In reality, this property was made to make images more accessible. Their goal is to describe images to people unable to see them. Thanks to Automatic Alternative Text for WordPress, you can have alt text generated for each image on your site automatically.
This plugin uses the Microsoft Azure Computer Vision API to analyze the content found in your images. As long as it is active, Automatic Alternative Text automatically adds an alt text for every image that you upload. According to the developer, this script automatically sets alt text if it is at least 15% confident in the result. You can find out more about it here.