you guys realize you are spewing bullshit out, right?
pp farming, by definition, does not impede progress, because by definition it does not mean that. anyway, this so-called "pp farming" is extremely important in becoming a pro player, not because of the pp, but because of the consistency aspect of osu! "Dumb mistakes" generally happen less as you practice fc-ing maps more. People who rarely ever try to FC maps and who push themselves without limiting themselves to the idea of FC-ing and potential pp end being more inconsistent than those who are accuracy whores and those who do this so-called "pp-farming" and FC-ing maps. And those people will never even have a chance in becoming pro unless they crack down and fix that problem. And trust me there are players who are like this. In my opinion, even jesus, king of g&r, suffers from this a bit.
It's one thing to be able to play something, which is usually what happens when people push themselves on maps they can barely pass, and it's another thing to master something, which is to be able to consistently play well and accurately, which comes from strengthening your foundations, i.e. playing and fc-ing the maps that aren't challenging, but not overly easy to full combo. You need to first push your limits a bit, but then back track (once you are able to read and play it) to master it.
And woobowiz is already doing this. He's fcing a bunch of maps, but he's also playing a bunch other maps that aren't in his videos. It's not like he's fc-ing maps way below his level. They are maps that will take quite a few runs to FC for woobowiz, which is good. I can't say how hard the maps he's playing are, or how much he's pushing himself, but he's obviously playing more maps than the ones in this thread.
And all pros have done this. They do this so-called "pp farming" even before pp was created, while also playing whatever they felt like, generally without any agenda. They played maps which they found fun, which usually were hard ones (because people generally like looking cool and awesome by playing hard maps).
And there are hard AR 8 + DT maps. Quite a few of them actually. They may not train you reaction time, but they still train your speed, stamina, aim, and even accuracy.