Social democracy is a capitalist economic system supplemented by large and robust welfare programs and a heavily regulated private sector. Things like strong anti-monopoly laws, relatively small wage gaps between workers and executives, strong unions, and progressive taxation are all characteristic of social democracy.

Democratic socialism is similar in many respects, but its long-term goal is to eliminate capitalism entirely by transitioning the means of production to public ownership. That does not necessarily entail communism, since most democratic socialists advocate maintaining a democratic system of government rather than adopting a one-party state.

I do not classify social democracy as socialism because its economy remains fundamentally capitalist.

I do consider democratic socialism to be a form of socialism, though with many important caveats. It does not inherently require or inevitably lead to communism.

I am personally less supportive of democratic socialism because I have a deep distrust of both the human condition and the long-term viability of a fully publicly owned economy. Historically, I do not believe such systems have produced consistently successful outcomes.

And you touched on a very interesting point that I rarely get to in discussions about socialism here on Lemmy: the human condition, the very nature of the human species. In my view, that's what negates socialism as a viable option. It's great on paper, and I even support it from a technical standpoint. It just doesn't work because, to rehash an old slogan, absolute power corrupts absolutely.