We use a human translation service for our company/product international websites. Yes, they’re still needed.

Do you take time to proofread and make sure your blog content is just right? If so, why not for the Spanish version?

I would also include an audio Spanish version, as machine-based text-to-speech is still very poor, especially for foreign languages.

Depending on if my audience are Spanish speaking people or not. If the topic is somewhat related to information technology I don't see the need (even me that I'm a Spanish speaker blog in English about programming from time to time).

I think the sweet spot would be machine translation reviewed by an human, i.e. convert your translators to reviewers/editors of machine translation.

I considered it, but I would need to repeat the operation every time I updated the original post. I make a hundred updates per month or so. It's not worth it.

In the corporate world Localization Teams are important and done by humans at my work

Thank you all for the comments