Flash drives, especially with USB3 are also MUCH faster.
Optical media is all but obsolete, IMO.
It's obsolete for short-term read/write, but it's superior in almost every way except for sealed spinning disk. For backups, writing critical data to optical disk and securing it in a fire safe or a temperature-controlled warehouse is about the best you can get for private, retrievable storage.
I've personally started writing encrypted backups to the Amazon cloud (Glacier), and it's insanely convenient; however, if they ever crack 2048-bit RSA encryption, my backups are as good as hacked. The BD-RWs I have in my fire safe, however, are not going anywhere and will survive the harshest fires.
Optical is definitely falling out of use, but it still has its place.