I want to open up the discussion of moving on to newer compression formats.

We use JPEG for images. Newer formats like WebP and AVIF now have good support from browsers.

We use AAC for audio. This is very commonly used and supported by devices. I don't see us changing this in the near future.

We use H.264/AVC for videos. While this has very good device support, newer codecs are improving rapidly while promising higher compression ratios (+ additional features). Personally, I see us going in the direction of AV1 (supposedly more open). I suggest transitioning gradually and, at least for a while, using a multi-codec strategy. For example, encode all resolutions with every codec or encode lower resolutions in AVC and higher resolutions in AV1. For this to make sense, the adoption of HLS / MPEG DASH should finally be the default in Opencast. In this way, players can select supported variants automatically.