In a context of "converting youtube into mp3", "technically not the best format" is an understatement for what most likely is "conversion" of 128 kbps aac or op

In a context of "converting youtube into mp3", "technically not the best format" is an understatement for what most likely is "conversion" of 128 kbps aac or opus into "320 kbps" mp3s (or whatever random bitrate). The least one could do is just listen to the aac/m4a or opus files without converting them yet another time.