Ubuntu server distributions are definitely general purpose.

So if I understand what you're saying, if someone asks you "Hey, could you recommend me a general purpose Linux distribution?", you'd recommend them Ubuntu Server rather than just straight up Ubuntu?

I'd agree both could be used in a general-purpose way, but I'd definitively call one of them more general-purpose than the other.

95% of my VM's run Ubuntu Server LTS, so yes, that is what I would recommend if I was a recommending person.

If they need a general purpose distro for a server, absolutely.

That would likely be a better recommendation than android.

But that wasn't the question, what they ask is specifically "Hey, could you recommend me a general purpose Linux distribution?", would you still first recommend Ubuntu Server?

Sure, why not?

Most Linux server distributions would be expected to be headless.

"General purpose" Linux distributions (not "server") typically would include a GUI desktop.

A GUI Linux distribution feels vastly more niche than a headless one.

Really?

What are some major Linux distributions that are only headless?

What is the market share of those Linux distributions compared to Linux distributions that have a GUI desktop?