The discontinuation of MPEG-1 Audio Layer 3 (MP3) was not a decision made by any specific organization or entity. Rather, it was the result of the emergence of newer, more efficient audio codecs such as Advanced Audio Coding (AAC) and Opus.
Although MP3 was a groundbreaking technology in the late 1990s and early 2000s, it had limitations in terms of audio quality and file size. AAC and Opus, on the other hand, were able to achieve higher quality audio at smaller file sizes due to improved compression algorithms.
Furthermore, the licensing requirements for MP3 encoders and decoders were more restrictive and expensive than those for AAC and Opus, leading to a shift in the industry towards these newer formats.
As a result, many software and hardware manufacturers have moved away from MP3 support and towards these newer codecs, leading to the eventual discontinuation of MP3 as a widely used audio format.