[kbrosnan]

Integration of a new decoder is not all that complicated code wise. What is complicated is the effects of the change and ongoing support.

1. Binary size cost, in my experience working on Firefox this is in the 100s of KiB range when adding a new decoder.

2. Ongoing costs increased compile times, new integration tests, functional tests and so forth. Keeping those tests passing and non-flaky.

3. Once something is accepted into the web ecosystem the intention is to support it for 10s of years if not forever. Web feature deprecation is quite slow, ex <keygen> & <blink>. The web has not deprecated a primary image format.

4. Security, a 'new' binary format is a place for security vulnerabilities, crashes and hangs. The web is actively hostile place for web browsers.