Taylor Callsen

Automatically populates Alt and Title tags for images featured in posts and pages, pulling directly from the values set in the Media Library. This makes it easy to manage your image metadata centrally in one place (the Media Library). Plugin also supports the ability to override the Alt/Title tag Media Library values by placing an Alt/Title tag directly on the attachment in the WordPress WYSIWYG Editor.
Tag population only occurs when viewing the post or page, and does not occur in the WYSIWYG editor.

Auto-populate Image ALT Tags from Media Library

Automatically populates Alt and Title tags for images using the values set in the Media Library.

Mario Peshev

DevriX

Lachezar Gadzhev

DX Webp Picture Tag Image Wrapper filters the content and replaces the img tags with picture tags by adding two sources – one with the image followed by .webp extension 
and one with the original image.
The plugin supports jpg, jpeg and png formats
Your site needs to support Webp images
DX Webp Picture Tag Image Wrapper resolves the issue with Accept header on Safari that doesn’t include the webp format. Using the picture tag 
allows the browser to render Webp images, if they are supported, without relying on that header

DX Webp Picture Tag Image Wrapper

Automatically wraps content images in picture tag by making one of the sources webp. It supports Gutenberg content

Auto-populate Image ALT Tags from Media Library vs DX Webp Picture Tag Image Wrapper