Earlier quoted context omitted.
It would have had to happen anyway. Skype's use of their customers' PCs for relaying traffic depended upon 1) users keeping their PCs turned on, and Skype running, constantly; and 2) users being tolerant of Skype consuming their computer's bandwidth and processor time. Both of these were starting to change by 2013, particularly as the market started shifting towards laptops (which are shut off frequently, often have…
Interesting lesson here I would say. It seems that relying too heavily on users with limited uptime computing power is not a good idea, until you reach a certain network size where it makes sense. The question now is, does this change with more computing devices with longer uptime (for e.g. a smart phone)?
Not in the slightest; in fact, that just makes the problem worse. Relaying data through a smartphone would force its radio to stay on constantly, draining the battery much faster than normal.