I'm pretty sure that if required, SVN could be updated to have an 'offline mode' where more offline operations would be allowed, since it keeps a local shadow copy of the last repository state from the server anyway. But offline mode simply isn't all that necessary anymore. How often is an average programmer in an area without any mobile coverage or other means of internet connectivity?

Shortly after git became popular, the Subversion team released a tool that enabled replicating a SVN repository or any subset to a local independent repository, which could be used for local development and re-synced to the main repository at any time.

Binary files can't be meaningfully merged. E.g. if two people create separate branches and work on the same Photoshop file, good luck trying to merge those changes, you can at best pick one version and the other user just wasted a lot of time. A lock communicates to other users "hey I'm currently working on that file, don't touch it" - this also means that lockable files must be write-only all the time unless explicitly locked - so that people don't "accidentially" start working on the file without acquiring a lock first. Apparently (as far as I have gathered so far from googling) git-lfs supports file locking but not vanilla git.