

The fuss is that every time you transcode to a new format you accumulatively lose quality.
So for example if you have an 320kbps mp3, but then that takes too much space so you transcode it to 192 mp3, but then you discover the opus codec is more efficient so you transcode it again, but then you want to make a fan video of the same song, so your video player transcoded it again into video friendly aac.
The quality on your final video is going contain the faults of all the files upstream.
Meanwhile if you edit the video from a lossless source, it will only get encoded once.
So it doesn’t matter for streaming, but it matters if you want to download and convert to other formats.
While not full proof, but you can always sandbox it with firejail or bubblewrap.
But make sure to read the documentation thoroughly.