Not sure I agree.
The kids I knew weren’t “acting like adults” in college - they were off.
Didn’t know how to hold a conversation, they were uncomfortable, and had a hard time with social cues and basic listening/including people in conversation.
If I had to speculate I’d guess they had a harder time modeling other people’s mental states along with just generally knowing less what to do - which I think comes from having less peer social exposure to learn from. This creates a feedback loop of social anxiety which can be limiting.
Part of the reason it may be hard to distinguish homeschooled people in the workplace is because they’re largely not there.
It’s hard enough to develop comfortable social skills even with siblings and a lot of exposure. I’d be worried that removing your kids from an environment where they’d get a lot of exposure makes this even harder for them in the long run.