It's a magnificent thing, the disposable diaper. My second kid is six months, using a good few each day. And it somehow costs barely anything. Much easier than washing cloths or whatever people did before.
Just the thought of all the plastic and other waste that'll probably float around for another few hundred years makes me sad. Humans really aren't such good stewards of the planet :(.
What's scarier is how plastic diapers are pushed in the developing world, specifically India - where there is no proper landfills, which escalates this problem considerably.
Modern washable diapers aren't what you parents used, they are slick and simple to use. highly recommended.