Inefficient does not mean ineffective, and it is certainly not the same as lazy. You get things done - just not in the most effective way possible. You're a bit sloppy, and use more energy. But don't feel bad about it. There is real value in not being the best.
Being busy can be good. It can mean you're being productive and getting things done. It can also be bad and signify that you're taking on too many activities and not giving yourself enough breathing room to relax and rest. My client ran into the Starbucks 30 minutes late for our career coaching session.
If you find it hard to get any real work done at your desk, it may not just mean you lack the ability to focus. It could also be your office's fault. Office design can influence how much productive work you get done in a day.