I mean, you can definitely get drives. I bought a LibreDrive-flashed USB 4k/UHD Blu-Ray drive last month, because I wanted to (legally) play UHD Blu-Ray movies on Linux

I don't know how much longer they'll be around, and the quality is generally higher than streamed video. I don't think that there will be a successor physical video format to UHD Blu-Ray, that this is basically the end of the line. But just saying...the infrastructure to use the optical media directly is not generally there any more, I think, on most out-of-box PCs. That's an additional barrier if you want to sell the stuff in that media format.

goes to skim Dell desktops

Yeah, it doesn't look like they have optical drives these days.

There's a difference between "people still buy them" and "people still buy them enough to recoup the investment in producing them."

Music studios have much larger budgets than indie game studios.

I built a desktop five years ago, and when I asked the Micro Center employee where the Blu Ray drives were, he looked at me like I had two heads, then pointed me to a sad little bin with loose drives with no boxes. People haven't had disc drives for a long time. Games are also getting so big that you'd either need to require UHD discs (even I don't have a drive for that) or multiple discs, and even back in the day, I hated multi disc installs.

Physical media on PC is as dead as it can get. I haven't touched an optical medium in the last 15 years, and i don't have a drive going on 10 years now. I also know of noone around me that is still using CDs/DVDs, the last time i messed with DVDs was when ripping every last one of them, and even my grandma has opted for converting her music to FLAC and freeing up the largish space her music Cds were using, making her collection both save from bitrot and a lot more readily available. I could get behind distribution per USB-Stick, but sticks that are fast enough to handle 100GB+ installations comfortably aren't cheap in comparison to optical media, and in most cases it would only mean they are used for a single time when copying them to a network storage, in the end just creating tech waste.

DRM-Free installers - that's where it's at, and that is what i store; alternatively, for PS1/2 games, compressed CD images are the way to go.

Collectors Editions are the exception, but even here I would prefer the USB stick format if it had redundancy built in - nowadays that is the truly universal storage that any computer can use without needing extra hardware.

ETA: To make the issue clearer: If i had to use physical media to store my game collection alone, i would have to rent a storage room to have enough physical space to store around 45000 titles, and then add even more to have available room for a few thousand music albums. It would making sure all this data is save from the inevitable demise of optical media a fulltime job. This is fine for a museum, it is not fine for a person which has to pay rent per square meter.