That depends on which skills you're looking for.

No online course is "the same" as in-person instruction for writing, language acquisition, music, critical thinking, anything evaluative or interpretive, or craft-based. Those kinds of skills flourish with or require dialogue and feedback and hands-on guidance.

I don't think I'd want a doctor to operate on me who boasted of their online training...

But you are certainly correct that many simple skills can be delivered through online courses.