Everyone seem to have had one or two truly innovative and game-changing app(s). That product might be their first product to give them reputation and big market share. After their first product, their efforts are into trying to keep up the current reputation and market share, as well as trying to capture remaining market with their non-innovative technologies.
R & D is something very vital for big players, I believe. And it's purpose should be to give, What the world need next ? If they capture it right they can blow away their competitor and world moves to their new technology. My idea is - don't create better than the old, create new. Else if your competitor created a "new" you have to worry.