This is a double-edged sword, isn’t it? I mean, yes, you have two layers in case the security of one gets broken, but at the same time, you also have two layers that could have bugs causing data loss.
Aside from that, multiple layers of encryption are often useful because they’re protecting against different issues - using TLS connections to transfer already-encrypted files, for instance. (This is also why it can make sense to use both block-level encryption and filesystem-level encryption.)