This is exactly my experience. On paper and in laboratory settings with 64-core machines and 128GB memory, AV1/AVIF is better in every way but in the real world it's too taxing on ordinary hardware.

AVIF uses AV1 as the codec, so I assume the hardware units used to accelerate video decoding should work for images too, at least when it matches the profiles supported by the hardware.

What hardware are you using? My Mac’s seem to handle large amounts of avif just fine without chugging.

WebP also has animation and transparency does it not?

(A little off topic?) but your comment made me appreciate AVIF.

Now if I may ask as I am not familiar with the encoder space but how good would AVIF be for say video streaming.

Like If I may ask, what's the best encoder for video live streaming in general (and is AVIF within the picture?) and an additional question being which is a good format for text based videos where there might be a huge amount of texts which might change (think a person showing terminal etc.), yes one can have a direct change of text which could be the most efficient and I am just asking it out of curiosity but what would be the second best option?

Huh? What is wrong with

  <video autoplay muted loop playsinline preload="auto">
    <source src="video.mp4" type="video/mp4">
  </video>
  

Nitpick - the question should have been:

> Why .avifs when we have .webps already?

Webp and avif are both image containers, both of which support animated images. The key difference here between avif|mp4 and webp|webm is the mime type and the associated UX with each of these. Image types are presented without controls, and are looping by default if they have multiple frames. Video types are presented with controls and with many other options.

It's a good question as to why avif though. Webp is entirely sufficient in most situations. Where AV1 as a codec shines is for more advanced compression, which may not be necessary for a simple looped gif-analog, but you'll still get some gains. The gains come at a processing speed tradeoff though, so they're good to use when you have advanced hardware on a low-bandwidth connection. I personally don't find the tradeoff worth it, so all of my media encoding pipelines opt for webp/webm by default.

1. How does one say that webm is the de facto standard? It’s common but not so ubiquitous that it can’t be replaced easily.

2. AVIF is a better codec with better compression, bit depth and hardware decode support.

Very different UX. They autoplay, no controls, no fullscreen, no sound, easy to copy, etc.

WebP also supports animation.

Alpha transparency is supported which you won't get with (normal) AV1 in MP4. The author seems more interested in the default behavior which seems like a waste since AV1 will do videos better.

smaller file size, transparency support and circumventing autoplay restrictions on Safari.

Since every frame is independent they can be quickly decoded