Those rates are utterly ridiculous because the work can be done from any location, a lot of these companies are in 2nd tier cities where the cost of living is very reasonable.
I won't even go into the opportunities of automating this stuff, but it's ridiculous...
But the hard part is selling it. I could easily run a team of 10 of these juniors who produce the same work (volume and quality) that generates $5m in revenue a year at the bigcorp, on a budget of 0.5m. Business wise it's almost free money, but without the big corp brand name, it's really hard to sell, even prices were cut by 50% or more and you put sales agents are ridiculous commissions. It's just crazy how important it is to clients to interface with a big brand name corp, despite the fact the actual people doing much of the work are on the level of interns. This is true for lots of finance/legal/consulting companies I find.