When you say Libreoffice maybe you mean a version of Microsoft office 365(about 3gb+ for some versions)? :-) I've noticed android SDK and Visual Studio SDKs can get pretty huge with .net+libraries

A lot of drive or disk failures were dust related. In you operate in a clean room you should be good . I found optical sensors picked up dust when a drive was open, and over as few years, scratches appear on the lens. Dust also got on optical surfaces when things were put down. I don't rate them.

Just because you bought a dodgy usb key, don't give up on spinning rust, SSDs or any other form of conventional drive. There's a reason your optical drive you revere has an ISA bus: Not many agree with you!

What color were the CDs? At one time, it was a way to tell the quality of the CD-R. Gold/Silver was considered good, while green/blue were the cheap CDs.

It didn't seem to have made any difference here. It was probably more likely because I used to write them at the fastest speeds my hardware could handle.

The first generation of CD-Rs used Cyanine dye, and didn't last long. Phthalocyanine and azo dyes are much more durable.

However, both CD-Rs and writable DVDs degrade rather quickly if exposed to sunlight. The reflective layer of a CD-R also tends to flake off if exposed to humidity.

No matter WHAT your media, there is always an advantage in storing it cool, dark, and dry.

IMHO, the dyes matter less. Optical media are exposed to anywhere they are stored; HDDs & SSDs are enclosed; NVMEs are not affected by normal dust and hard to get at. There's also the fact that in a 4.7GB optical dvd, I could fit 4-6×2TB nvmes.

I don't think they'll die, due to audio & film or series demand for merchandise. So writers & readers will exist. To me, your penchant for optical storage is a bit like the valve/transistor thing in the 1960s. Responsible persisted in specifying valves for audio (and indeed some tv parts) long after transistors had proven themselves superior & better at the job. They never woke up & smelled the coffee.

It is common knowledge in the industry that the Cyanine dye degraded quite quickly. It was only used early on.You can simply store them in a box and make sure it isn't subjected to high temperatures.

UV is the issue. I accidentally left a box of blank CD-Rs sitting on the window sill for over a year, and I was sure they were ruined. But it turned out that the transparent plastic box must have excellent UV blocking properties, because they were fine. A few discs left beside the box were visibly discoloured and unusable.

HDDs are quite durable but as I mentioned earlier, consumer-grade SSDs and NVMEs are rated for 1 year of offline storage, no more. After that, electron leakage means you absolutely will lose data.

Flash memory simply isn't an offline storage medium.