You can be the most verbally eloquent person that people knew, and still not good at conversing. You can be as awkward, stiff, out of place, etc.
Those are still two different things, even if both involves the use of languages.
In my case;
I don't have speech delay -- possibly just a reason why I pass off as an aspie merely because I'm physically capable. I have no speech issues.
I have no stuttering, I had no issues with pronunciations, I had no hearing problems, I don't have any form of mutism. I don't have issues with tones most at the time.
Just because I like physically saying and the sounds of the words, or sing over and over like a stim, that doesn't mean the same with the words and context themselves nor even the notion of social conversation.
Somewhat I do struggle a bit with volume control when my emotions are a bit on the prioritized side. And then there's expressing, monitoring, controlling, etc.
None of these made usage of spoken language more natural. It didn't gave me better wording.
To me it's more of a weight that I have to constantly afford whenever any possible communication could happen, all because everyone assumes that I could therefore should. And I don't like scripting.
Speech without issues only gives one factor, a factor that rules out the issues of being capable of physical speech and that's just it.
That only likely factors like, say, confidence that not getting make fun of or get others infuriated for sounding funny or weird, than language skills itself.
It's like not having minus points for having something undesirable about your physical capacity of speaking, a less thing to get worried or be insecured about. The rest is just in the individual.
For me that's just all it -- part of validation, a grand accessory for passing, and a grand convenience.
Language usage doesn't grant knowing the whens of initiating, reply, and end of conversation.
Worse, this is also partially EF, as is it seem all social skills are. My emotional and social maturity weighs more with that than just the capacity of speech and 'right' wordings alone.