> Security professionals generally recommend avoiding reliance on any single encryption system and instead evaluating well-reviewed full-disk encryption alternatives such as VeraCrypt.

What does this even mean? Nobody is using multiple encryption schemes on top of each other, are they?

I've heard this before, so what I think it means is this:

If you want to encrypt some data that gets stored persistently somewhere on your machine, rather than invent an application-specific encryption scheme for that data alone, instead use a mainstream full-partition encryption mechanism, then store the data as plaintext within said partition.