Now imagine crossing the border, connecting to a new telco and being prompted to choose a data plan (or a phone number). This would be great! I’d purchase new phone number / data plan every time I’d cross the border. Telcos would profit from this and I wouldn’t have to spend time researching the best package (I will be presented with the options right in the popup on my phone)
The author has a very optimistic view of cellular companies -- in many countries, the official carrier rates for SIM's are far worse than those available from resellers, so the "Click here to roam" rates are not likely to be the "best options"
If telcos really wanted to give fair rates to roaming customers, they'd just negotiate more reasonable roaming rates so visitors wouldn't feel the need to buy a local SIM in the first place.