Upanishads

I asked about 'things', not people. But I guess people are things in a sense.

If you say all things are equal, then the idea of the supreme is a bit redundant I'd have thought, unless we say the supreme is not a thing.

Where people are concerned, it doesn't seem to be borne out by the facts of experience. Even on the bodily level, some are the inheritors of superior genes, which give them a better body. Others may be born with some congenital disease etc etc. There are enormous variences in the level of intelligence too.
In my view, everyone is not equal, although they should all be treated with a proper consideration for their human rights etc.

I'd say though that no thing is actually supreme. Everything exists within a field of being - the universe if you like - and all enjoy a relative existence.
Some say that each and evey thing is a sign or symbol of the supreme which exists behind all visible or manifest existences.