[zamadatix]

It's really not bad:

    <picture>
    <source srcset="image.webp" type="image/webp" />
    <img src="image.jpg">
    </picture>

and you only need to bother with this on images it might matter (e.g. key large multi MB photos in a blog post or something not all of the 20x20 logo icons that would be less than 2kb even if uncompressed).

[kixiQu]

The HTML isn't bad, sure, but the process of generating appropriately scaled and formatted copies of images can be if you don't have other build steps that require similar automation.

[zamadatix]

Appropriately scaled is always a problem at which point you hit save/export twice and you've done everything you need.

Unless rescaling an image itself is already too much work, in which case this has nothing to do with image formats or plain HTML sites in the first place.