Depends on what you are connecting to on each side of the converter and what you want to put through it (what type of audio content) and the resulting experience you want to get. In other words, ...
You get the same nostalgic rush replaying retro games, armed with old tricks. Most TVs still have RF or AV/RCA ports; use RCA ...
HDMI is the norm for a lot of devices these days, but there are times when you need something more than HDMI. Whether you need to connect to RCA or Optical (SPDIF) or even just headphones, an audio ...