Alt Text is a word or phrase that set out the image on the web. Google has proclaimed that the search engine will focus on Alt text analysis, so Alt tag of image is very impotent for SEO.
Magento 2 Image Alt Tags extension improves ranks of product images in Google image search. And overall benefit is that it improves overall SEO score of website. This extension does not effect to the database of your magento 2 store. Image Alt Tags Magento 2 extension does not collect, store and share any user data, therefore this extension is GDPR-compliant.