After reading some posts here on the advantages of using source control for a single developer, it seems to me that the main advantage is that I will have backups of all changes to the source files. Delphi has a built-in history function that does this by default.
Is this really the same or should I use a ‘real’ source control tool instead?
The history function does not maintain history indefinitely, and you may delete the __history directory one day, whether it’s because you consider it cruft, or because you’re archiving the project, etc.
If you ever release your source code – i.e. send it to third parties – you’ll want to be able to keep track of what you actually released. Labeling can help with this in a source control system; branching can then let you apply patches to a previously released version, without doing contortions such as maintaining multiple directories with the same source code in various degrees of advancement.