I know what you mean, I mean the same thing. In 20 years time I fully expect that a Adobe Photoshop (or something 100% equivalent) will be a web app. Sure, it can't be done reasonably today, but for every single roadblock preventing it there will be many competent engineers capable of removing that one roadblock and many people (developers and users) providing a strong incentive to do so.
Adobe is already trying to create a web version of Photoshop. Eventually, they'll get to full compatability but I don't think the web adds a unique advantage to Photoshop; likely they're just doing it to cut down on piracy figures.
One place where the web apps can excel is in replacing 3D modelers. Once we get to the point that the frontend can be done quickly in JS, then the entire backend (e.g. rendering) can be done on a server-side cloud.
Imagine being able to lease server time so that what was a 10hour job, is now a 1 hour job?
