I'm not sure about the title, which just seems weird.
But I think the broad point in the short post is right. Objective-C may look horrible today, but compared to the other choices at the time of its debut; it looked pretty damned good and even better because it was what NeXT was attaching its UI tooling to -- and compared to what was around at the time InterfaceBuilder was unreal good.
It's hard to know how to answer without knowing more. I slack off when I don't love the work. Whereas when I am building something that I think is really cool, you can't keep me away from the keyboard. When I'm a cog in the machine, I struggle to do more than the 10% you are doing.
First question I'd ask myself would be: "Why do I think this would be better elsewhere?" Is the issue Google, or is the issue you/the profession?
Depending on the answer it seems like there are a few reasonable landing zones: 1) find a new job at google that addresses the perceived issues at google. 2) jump to a new job at a new company that addresses the perceived issues at google. 3) approach your current job with a new attitude to work harder and do more. maybe set your sights on next promo. 4) embrace your slacking, saving money to prepare for a career change.