Modularity and separation of concerns can extend into other domains than software.
For me, it seems so much simpler to keep the two separate. You won't be forced to wash the heating element every time you wash the cup. Can't heat a different cup while the other is in the dishwasher, unless all your cups are self-heating. Normally, the only way for a cup to break is if it shatters, but with an inbuilt heater there's electronics that can break too. And should the cup shatter, now the heater is unusable too, or vice versa.
I have to have a kettle for other purpose (including heating water for other mugs than mine), and no self-heating mug is going to be as efficient as a kettle to heat water.
Furthermore, I also put cold or room temperature liquids in my mug. With a self-heating one, I would be carrying the heating parts for absolutely no reason.
Same goes for a TV.
By keeping things separated, I can decide what I do which each device and manage their lifecycle separately.
If the device reading video files is included in the TV, I can't plug it to another TV or a projector or even take it with me to use it elsewhere.
While I've upgraded three times my video playing device to follow tech evolution, I've kept the same TV to plug them in.
I have a multi-purpose kettle that I can use to boil water, heat the room, cook a small amount of food, or use as a sand battery for when its cold in the desert, where the kettle is designed to operate as long as there is a handful of material to burn.
It is fair to observe a separation methodology, but I also have to say, in some cases multi-purpose devices have their place.
If, say, the self-heating mug involved solar harvesting, I'd put a couple in my kettle bag, for sure.
You can make coffee with a kettle, but if you are making enough coffee often enough, it does make sense to bundle a second kettle into a dedicated coffeemaker, even if you are reducing the functionality of it by doing so.
It's a thing and it's convenient as a smart TV is convenient for people who don't care much.
But as a "power user" of a TV, I want to compose my own setup.
In the same way, "power users" of coffee don't use a coffeemaker. They use things like French press.
(I use instant coffee myself in my non-heating mug so in this comparison I would be the person not owning a TV and watching everything on their phone?)
Arguably the outcome you’d want there is to be able to add your own kettle to the coffee maker, so you can have the best value/option for you if you want it. Want a cheap thing or none? Fine. Want one with remote start and modded temp controls or whatever? Fill your boots. Got a new coffee part but like the existing kettle? Reuse it.
This applies less for some physical items, I know some people are already preparing to explain why it’d be harder to make or dangerous or something but that would miss the point. Computers are incredibly easy to swap out, we already have so many ways of doing that.
Maybe I want a fast computer. None. Maybe I want to upgrade later. Maybe in a year there’s a faster cheaper one. Maybe mine is just fine right now but I need a new screen. Why do I need to bundle the two things together? There’s a simplicity for users unboxing something but there’s not (I think) an enormous blocker to having something interchangeable here.
This provides absolutely zero advantages to the oven or to the microwave. It does cause a lot of stupid, easily foreseeable problems:
- There's only one control panel, and if the oven is currently active, some of the microwave controls get disabled.
- The microwave is awful in various ways -- regardless of whether the oven is active -- which wouldn't ordinarily be a problem, because microwaves are very cheap. But...
- It's impossible to replace the microwave, a $50 device, without simultaneously replacing the oven, a $2000 device.
