None of us here are Brahman. If we were as you explained we would be freed from sanskars and bondage etc. So if we were Brahman we would have been freed from life and death, old age, disease but we are not. In addition, we would be able to to some extent change the environment in a positive way.
I believe that having knowledge, realising something and experiencing it are three different things. By mere knowledge and speculation we cannot say we have attained Brahman.
However when we declare ‘you are this universe’ or ‘I am this universe’ we come from the assumption that we have attained Brahman which is not true as we all are bonded. As I explained there is a huge difference in knowing, realising and truly-realising/attaining/experiencing.