I think moving away from Adobe's offering is lot harder than you can imagine. Not a lot of big business want to move away from the Adobe's Photoshop and Illustrator products.
There are free alternatives and cheap ones. But these two products are like giants which are not easy to replace. And any new generation of designers and developers who wishes to land job, choose these products.
People who have experience can switch to new alternatives. But existing business and the designers who are relying on these tools for their everyday job, I don't see them switching to alternative. Some products from Adobe are lot better and it'd be foolish to switch to alternatives.