Making a program that is so usable it is easy is the ultimate goal.

Once a program or product has achieved it I believe there will be a natural tendency for everyone to copy the market leader.

If you are in software development I think you should accept that software cycles will eventually stagnate on individual products and you or your company should be constantly seeking to find or build new products. Software has the potential to be immortal (that was the promise of the digital age) and as a mathematical solution I guess there is an optimal or at least near optimal solution.

There's a heck of a lot of areas where the software needs improving. I've got a Windows Surface and while the OS is great some of the applications in the store are terrible. Spelling mistakes in menus and really poor content and layout. There's a lot of good work still to do in the majority of software genres.