I haven't been following comics long enough to have seen many reboots to compare, but for the examples you gave, I think it may be that Superman is still supposed to be the same character. He's largely intact in terms of powers, supporting cast, concept, and role, though details, even significant ones, may have changed.

Lobo on the other hand became a new character, literally, and dropped many of his previously defining traits. This includes, to my knowledge (I haven't read anything with the new version, or the old for that matter) his concept as a parody of over the top 90s characters. The new Lobo might be fine in his own right, but doesn't carry over anything that makes him Lobo. If Superman had been reinvented as a low-powered, raised as an alien, supporting character in a different book, that might be similar, since you've abandoned some core themes, concepts, and elements.