This is only partly true. It may seem like a profound observation and in one sense its true; in this moment, I am what I am.
But it can be harmful and self-limiting. It’s harmful when used as an excuse for poor behaviour. For example, in workplace mediation and couples therapy I’ve often heard it used (defiantly), to justify behaviour that offends another person.
It’s self limiting if you believe that being what you are is fixed and final; it precludes personal growth, change and learning. It also takes away from the self as it denies one’s ‘sense of agency’.
“I am as I am” might be better, or even, “I was as I was (back then)”.