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?