I really like using command line arguments. I think that it is a flexible way to interact with and configure my games/engine.
It is for example easier to just add a --log-verbose=resource to set all logging in the “resource”-domain to verbose or
--memory-enable-stacktrace=render to enable save of stacktraces for all allocations done in the “render”-allocator than to
edit some config-file somewhere. At least for things such as the ones mentioned above, that is only set once in a while.