When is the last time you saw a C battery?
I'll bet that there two battery types shown above you haven't seen in a long time, and one you didn't even know existed.
The ones you haven't seen in a long time are probably D and C, while AA, AAA and PP3 (usually called a 9-volt) are very common. You use AA and AAA in remotes and PP3 in fire alarms among other things.
AAAA does exist, and a typical application is a Streamlight stylus pen light. Pen lights like that are used for things like forensic investigating, forged document detection, seeing HVAC leaks and things like that. So unless you've ever used a Streamlight stylus pen light, you've probably never seen an AAAA battery. But now you at least know what they're used for.
A battery I've not seen in years is the C size. The last time I saw one was probably 30 years ago when I was a kid. I'm not kidding. I used them in Casiotone keyboards that my parents bought me, and maybe a portable stereo "boom box" or two. Other than that, I've not seen a C battery since.
The C is still made, and cheap to buy. But don't ask me what electronic device uses C these days, because I can't think of one.
Will the C ever stop being made? No. Take the oldest electronic device you own that uses a battery, like a really old cordless phone, and chances are very good you'll be able to find a replacement on eBay for it easily. You could have a cordless phone that went out of production 30 years ago, and you will find new replacement batteries for it today. That battery will probably cost anywhere from 15 to 30 bucks, but the point is you can get one. Someone made it, and you can buy it.
And if you want to talk about things that use ultra-proprietary batteries, that would be old laptop computers. But I'll bet that even if you own something really old and obscure, a new replacement battery for it will be on eBay.
Concerning the C, I can see it at some point becoming special-order-only, because like I said, I can't think of a single thing that uses that battery size.
Why the size difference in AA, AAA, AAAA, C and D when they're all 1.5 volts?
The answer is current. The bigger the battery, the more current it can give, and that pretty much explains why almost nothing is made that uses a C anymore.
An electric device that needs strong current, like a portable radio with larger speakers, will require D size to work properly. For electric devices that need minimal current, like a remote control, AA and AAA work fine for that.
C is that size that's too big to be compact and too small to deliver enough current in larger electrical devices.
I don't pine for the days when the C was common and actually needed. But it is interesting that size hasn't been shelved back to just a special-order-only type.