Even signing with pen and paper is a baggage we're carrying with hardly any guarantee of identification, and has challenges like your signature being too simple

Even signing with pen and paper is a baggage we're carrying with hardly any guarantee of identification, and has challenges like your signature being too simple or changing over time. This is utterly rubbish and should be made obsolete in the digital age, IMHO. Where are the finger print scanners or iris scanners when we need them?