The difference in user experience between HTML apps that don't even _try_ to cache anything locally vs mobile apps that sync in the background and cache things locally is night and day and it just gets bigger and bigger as your bandwidth quality gets worse.
This is the biggest reason why I'm concerned for the future of the open web.
I agree 100% with your general sentiment, but just to nitpick:
You would have to really cherry pick the worst case possible scenario to be paying R1 per GB and even then R1024 is $82.44.
Contracts come with data included, all the networks have data bundles, most of them run frequent 2-for-1 style promotion deals and you could always shop around.
Once you factor in all of that, mobile bandwidth is pretty on par with most of the world. Really expensive when you take into account people's incomes, though.
ADSL and other fixed line / point-to-point options are much cheaper once you require anything more than a tiny amount of data, but still really expensive considering the typical South African's income.
Things are very different from the first world, but you have to factor in physics too - we're at the opposite end of the world of just about anything you would want to connect to (latency!), our neighbours didn't all have connections already set up that we could just piggy-back off, etc.
I'm pretty convinced that self driving cars can fix this. Reaction times will be much faster and they can network together to spread out the braking and acceleration. Possibly even merging at high speed.
A more powerful potential mechanism is that they can be programmed to respect do not enter directives from a traffic control system (keeping human drivers off a freeway would take a lot of infrastructure). So the amount of traffic on the road can be regulated to keep it below the capacity implied by the safe response time of the vehicles.
If an image fails to load, the browser draws a little box with some alternate text describing that box. If the CSS doesn't load, your text and content is displayed in a weird font without the grid layout you were using, but if you wrote your HTML semantically (using <h1> instead of <div class="title"> etc.), the browser can still show most of your content, and you can still move around on the page.
There is a LOT of lithium in the world and that's just near the surface - you can always dig down.
But at that scale you don't have to use lithium anyway. When it comes to grid or off-grid storage, you don't need the best energy density as cost per watt-hour is probably the most important factor and there are already other chemistries on the market that will work just fine with many more on the way. Sodium or Aluminium based batteries seem particularly promising.
In South Africa we're having rolling blackouts called "load shedding" because we don't have enough power. Exactly why is a long and obviously controversial story, but in short: Mega projects that were supposed to fill in the gaps are being delayed, maintenance on existing infrastructure was delayed in the hope that the new projects would come online in time, but that's now causing cascading failures and maintenance cannot be avoided any longer, causing even more outages..
So we don't have grid power 24/7 anymore and our electricity prices (that used to be some of the cheapest in the world) are now skyrocketing. So I would imagine that many many people here might be in the market for something like this at the right price.
I've actually been looking into playing with some LiFePO4 batteries and trying to see how big of a UPS you can build for, say, R5000 or R10000. LiFe batteries have longer lifetimes, are safer (less likely to catch fire or explode), are less finicky about how they get charged (more like lead-acid), seem to be potentially a bit cheaper, easier to use in multi-cell configurations (cell-balancing issue related), etc. You can also source or sink more current, so faster to charge/discharge. Downside is 14% less energy density which is why they don't get used in laptops or smartphones and (in Tesla's case) sometimes also not in cars. But that's not much of a downside for (off-)grid storage..
Pretty sure there's a gap in the market there just waiting for someone to jump into. And once you already have a giant battery it is probably that much easier to convince yourself of covering your roof in solar panels, getting a gas stove and disconnecting yourself from the grid entirely :)