Pretty obviously to me the difference is the available material. Becoming fast in 2010 was extremely "DIY". Just something like say, a better way to solve an F2L pair, was not easy to simply find on the internet. You don't really have to wonder "how to I get faster" now, there is more media than you could ever consume laid out for every stage from beginner cuber to sub-6. This was not always the case. This site was probably your best shot, or else other small forums scattered across the internet. There's also the aspect where a lot of stuff now is considered "settled science" that used to be controversial or experimental. It wasn't so terribly long ago when people doubted if ZBLL was ever going to be viable.
You can probably notice that cubers from that era tend towards a certain kind of person, often into CS/math, who was an avid internet user back when not everyone was. The average cuber also used to be a little older than they are now.
The volume of cubing content and ubiquitousness of the internet has made even high level cubing much more accessible, particularly to young people.