This is not a technology problem. This is a business problem. If you are running a shopfront, online or offline, in a competitive marketplace, you need to make it as accessible as possible to all the customers you want. For eBay, that is "everyone" (for a hot-dog stand, it is also "everyone"; for a Rolex dealer, it's only people who can afford a Rolex). The higher you make the barrier to entry, the fewer customers you will have.
Now if you're a person wanting a partner to sell your stuff with, do you want the stupid partner, or the smart one?
If you're a customer wanting to buy, do you use the easy website that works, or the one that doesn't work right? What incentive is there for you to use the hard-to-use site?
eBay thinks they have incentives (product range, large base of existing users, etc) to overcome these things. They may be right. They could be wrong. It's their business choice to make it work less well for some people. If they are unable to make it both work better for some people and well enough for others, they may have a serious business problem; if they choose to make it better for some people and worse for others, that's a courageous business choice. If it makes them, or their sellers, less money, it's stupid.
Search for Terrestrial Intelligence is currently in progress but has not produced any good evidence of intelligent life on that planetary object yet.
"Personal responsibility... try it!"
Oh stop being stupid with that red herring!
This isn't about "personal responsibility".
It's about transfer of effort and risk from the company billing you to you yourself.
And about companies removing a service that they have led you to expect will be available. This person is expecting to pay their last bill online, like they expected to (and succeeded in) paying their previous bills online.
"Paperless" or "Online" billing simply makes it entirely your own problem to remember to make the regular effort to access the billing information and print it off or save it (and back it up). It does not remove the requirement to keep your own archives for as long as you need them (which for financial information is as long as the taxman can ask for it!)
Many companies can and will blame you when you don't have a copy of the billing information because you didn't download it or relied on them to keep it available, from utilities to banks.
So the only way is to either archive it yourself, religiously, or have them send you bills.
$30 payment for going paperless, as offered by my bank? $30 doesn't pay for very much of my time spent downloading and saving records. I'll stick to having my bank send me the information in a handy-to-archive form on durable media so I don't have to think about it.
In some parts of the world, notably the North American continent, one cannot expect SMS between carriers to work properly; there are many missing routes, including where there is a route from carrier A to carrier B but not from B to A so you can't get a reply to your SMS. Also even when it works it can be very slow, transit times of hours are within my experience.
It's not like Europe where SMS can be expected to work so well that it effectively always works and is fast.
Of course the North American telcos still charge you for your SMS when it disappears into hyperspace because their network isn't configured properly, but I'm sure you all expected that.
While it is true that SMS is carried in the control channel of GSM  and that control channel has reserved bandwidth not available for voice call channels, it is also true that heavy SMS traffic will saturate this control channel and that some carriers have had to increase the control channel bandwidth in order to make room for the volume of SMS. You can observe the control channel saturation (and resulting inability to set up new calls, while existing calls continue fine) in any major city in the UK from around 23:45 on 31 December to 00:30 on 1st January. So the carriers do have to put a bit more bandwidth into lots of SMS.
However there is also an SMS messaging centre to operate, which is a pile of computers to route messages, as well as storage on each cell base station for the SMS waiting to be transmitted to the handset - rather like email it's too cheap to meter, except for all those mail servers you need to forward and store the email.
The profit margin on SMS is clearly huge (consider that bulk SMS rates are at most half the cost of single SMS out-of-plan from a handset in the UK) but it's not 100% profit and 0% cost.
And finally, think about spam: the reason you don't get much SMS spam (compared to email) is that it costs quite a lot to send SMS compared to email. If you make SMS as cheap as email, you'll make it as spammy as email, and you need to think about how to avoid that.
 I'm going to ignore CDMA here, I wish the rest of the world would do the same.
"Experience has proved that some people indeed know everything." -- Russell Baker