I thought there was some small chance they could succeed in lower income countries but before they were able to get a foothold chips got cheaper and Android was able to run on equivalently low-end hardware.
Recently botnets haven't really been the issue, they've mostly been reflection attacks which use DNS, NTP, etc. to amplify the size of the requests. If networks started to drop UDP packets with spoofed addresses that would reduce the problem significantly (so would convincing a huge number of people to fix their DNS or NTP servers, but that is harder).
I'm not sure how it is in other countries but in Canada there are quite a few things landlord as originals that appear to simply be content they are the exclusive regional distributor for rather than the creator.
Everyone I know that used Google Talk switched to Hangouts for the simple reason it was a continuation (though the EOL of the desktop application in favour of a shitty browser plugin was dumb), Allo/Duo however is completely moronic as they exist in parallel are disconnected. I haven't installed Duo, and won't be installing Allo, I'm sure as a Nexus user they'll eventually appear on my devices but I'll disable them at that point.
Maybe this depends on what you're referring to as self-guided but the in vogue approach of not teaching multiplication tables, long division, etc. has shown to result in a poorer understanding of mathematics.