I have a Blu-ray drive, though my case doesn’t have 5.25” bays, so I just have the SATA cables come put the side.
The sole reason I have it is because once a couple years back, I wanted to watch the Star Trek: TNG Spanish dub, which was only available in the US on a Bluray, which I promptly borrowed from my local library.
I have used it a couple times after, though - once to burn a CD-R with TinyCore to boot on a Pentium II laptop, and once to backup a Bluray with a dub only available on that medium.