Flash memory will always be more expensive, not to mention that long-term data retention is not its strongest point.
That's why the advances in Disc media has been moved more along the line of archiving now but there isn't much of a future for it on the consumer side .
Think about this as cheap as disc are to make who is going to buy a Blu-ray burner nowadays? and even after you make these 100GB Blu-rays how many people will have a way of using these Blu-ray XL?
Cards are steadily selling & advancing we will have SD Express & Micro SD Expess cards with almost 1GB/s transfer rates with a max storage of 128TB & CFexpress with even better specs over the next few months & they are backwards compatible with the devices we already have
Take the Xbox Maverick & the Xbox One games being playable on Windows 10 devices situation , Blu-ray disc are useless in these situations but a SD card can be plugged right into most Windows 10 devices & if Maverick doesn't have a SD drive it can be attached with a cheap adapter.