SVN is not only a UI. If you get deeper into how scm's are implemented you should be able to appreciate the differences and tradeoffs between SVN and git. For one, git completely fails at bigger repos. It is just the reality.
For me the most amazing thing about git is how it is built out of very simple blocks. Each commit or object is a simple hash of it's contents. Which is just brilliant really. That's why it so fast and avoids any potential data corruption.
The killer "feature" of SVN is partial checkouts. If im not mistaken, perforce and bitkeeper have this feature.