What jobs/tasks is Damn Small Linux (DSL) the best at?

Compared to other recent distros (and it's perhaps no longer fair to call DSL "recent"), the main thing would be compatibility with old hardware, particularly from the 90s era.

For simply running on the earliest possible hardware, I'd say a distro called BasicLinux has it slightly beat, as it can run comfortably on a i486 and use the X windowing system. But it comes with very few drivers, so I wouldn't say that it is overall more compatible with 90s era hardware than DSL. Well perhaps late 80s era hardware if you have a 386, which wouldn't run at all with DSL, but I think that's stretching it.

If someone had cause to run lots of virtual machines, such as for network testing, DSL would put a light load on the host hardware. BasicLinux would be better still in that regard, but might take a lot more work to set up.

On a personal note, one of the things I like about DSL above most other distros is that it doesn't have too many complicated background programs and scripts to manage the configuration of the system, so one can dive in and change things without fighting against too many systems that change them back or simply break. Plus I'm posting from a Pentium I, and not many modern distros would allow me to do that comfortably.