The fundamental problem with Subversion branches, at least in my view, is that you have to know ahead of time that you want a branch. Perhaps this isn't a problem for you, but it is for me. Sometimes I find myself thinking, "Hang on, is this really the right way to solve this problem?" In Git, I can save my current work in a branch, trot back a few revisions, and try a different approach.
In contrast, Subversion encourages a largely linear style of development. I expect some people, like yourself, prefer this approach, finding it conceptually simpler. And that's fine; I'm not saying that's wrong or bad, or that you should stop using Subversion. That's clearly what you're most comfortable with.
But a linear development model isn't for everyone. Those of us who like to experiment and backtrack tend to develop in a tree-like fashion, branching off shoots all over the place and pruning the ones that turn out to be a dead end. For this style of development, Git's branching model is significantly better than Subversion's.
"obviously you'd never actually do all this in SVN if you were sensible"
Exactly. You'd never do it. You don't need to do it. You can get the job done without doing it. And that's what matters.
Git fanboys are hilarious sometimes...every argument is made from the position that none of the rest of us really understand git, and that if only we did, we'd fall in love with git in all of it's fiddly glory. What they miss is that many of us hate complexity, and we avoid complexity that doesn't justify itself with true functional advantages.
I like simple tools that get the job done. Git makes my life harder; I have to think about more things to do the same, basic tasks that were made trivially easy in subversion. That's the point.