This is really only a thing with devices that take low voltage consumer batters (AA, AAA and the like) for reasons already described. There’s tons of devices with a single battery, sometimes an embedded one and sometimes removable. My camera, for instance, takes a proprietary battery and has its own charger. My phone and laptop have an integrated battery. I have a lot of devices that take a single small button cell batteries that are used in watches. I have tools from an electric screwdriver to a leaf blower that all take single proprietary batteries.

Van Halen made some great records, but that first one was never really surpassed in many ways

I‘m not sure I agree you on “nobody asked for more power”. A lot of people don’t want a sluggish car when they are trying to merge. People “ask” via their buying patterns. They’ll look to a V6 if the 4 banger is too puny. They‘ll look to a competitor.

Branch outside American-language films and look at how things like Italian Neorealism and various New Wave cinema changed movie making.

Enter Sandman

Casablanca

limiting to 5 is tough:

Vampyr (with honorable mention of Nosferatu)

Ugetsu

Rosemary’s Baby

The Shining

Jaws