From RFC4122: "A UUID is an identifier that is unique across both space and time, with respect to the space of all UUIDs."

Hard to achieve if everyone starts from 00000000-0000-0000-0000-000000000000.

Right that’s why nobody starts at 0. And you don’t have to only add 1 to be ordered, no DB I’m aware of just adds 1 to sequential UUIDs. There’s always randomness/entropy involved.

Sequential UUIDs don’t start at 0. They are a 128-bit composite of two integers; a temporal component in the high order bits and a random component in the low order bits.