Why a universal converter earns its place
Audio comes in dozens of formats — MP3, WAV, FLAC, AAC, OGG, M4A, WMA, and more — each with its own trade-offs between compression, quality, and compatibility, and most people don't want to research codec details every time they just need a file to play on a specific device or app. A universal converter's real value is removing that research step: pick the target format the destination actually needs, and let the tool handle the technical details of getting there.
The underlying rules don't disappear, they're just handled for you
Converting between two lossy formats (say, WMA to MP3) still involves the same lossy-to-lossy consideration discussed elsewhere — a second compression pass on already-compressed content. Converting from a lossless format down to a lossy one still involves the same permanent, one-way quality trade-off. A universal converter doesn't change these underlying realities; it just means you don't need to manually pick different tools or workflows for each specific format pair, since the same conversion principles apply universally regardless of which two formats are actually involved.
The most common reason people reach for one
Compatibility mismatches are the dominant use case: a file downloaded in one format that a specific app or device won't open, audio extracted from one context that needs to fit into a different pipeline's expected format, or simply not knowing what format a particular piece of software or hardware actually needs and wanting one tool that covers whatever the answer turns out to be.
Knowing your source and destination still helps
Even with a tool that handles every format, knowing roughly what your source file already is (lossy or lossless) and what the destination genuinely requires (a specific format for compatibility, or just "smaller," or just "good quality") lets you pick sensible settings rather than defaults — the tool removes the need to know codec implementation details, not the value of understanding what you're actually trying to achieve.