When it's welfare, you have one monopolistic "service" provider, which ends up getting managed by bureaucratic means (to ensure low graft and wastage, leading paradoxically to a specific and growing amount of wastage as the bureaucracy expands, but that's a different point).

With charity, you have multiple providers, and they compete for funding from contributors so are incented to be as maximally efficient as the charitable services market allows.

And quite frankly, I'd rather live in a charitable society than a welfare society.