I've seen people converting to DNG rather than process the raw files but I don't know why?
The videos are explanatory. The advantages of DNG are minuscule, the disadvantages are huge (to me). I don't recommend it. Reasons: 1) Backups. Lightroom saves metadata in the DNG file. So with any change in LR, you actually change the file. There is no option to save xmp sidecars next to DNGs as you can do with raw files. This creates a back up nightmare. 2) Data. Adobe says it's a lossless conversion. Do you believe it? I'd rather always have the raw data and not risk any adobe conversion artefacts to save a few megabytes.
Lightroom is Non-destructive. Any change you make are saved separate from the file. To embed the data into the file you have to save the meta data (ctrl/Cmd+S) to the file but it is still NON destructive as you can step forwards or backwards through the changes. This goes for .DNG and .RAW. Data conversion is only lost if you select that option to save a few MB. If you do not it stays the same. Try it some time by looking at a .CR2 vs .DNG (converted without the conversion to smaller file size) they are identical.
On the .DNG note. Adobe has committed to support the format for years to come. Who knows when .CR2 or the other .RAW formats will change at the whim of the camera gods. I see zero difference between the two formats and use both.