My thrones(there’s 3) are over 30 years old. I do my business and I flush. They fill and wait till I have the urge. There have been times the flapper didn’t drop and seal. I’ve replaced tank internals once or twice. Fill level is adjustable but a little more water means a lot less flushing. I’d bet my old fixtures are as efficient as the new ones. Granted they don’t save water like crapping on the sidewalks but I like my privacy.
I hadn't thought of the green aspect of crapping in the street. Maybe someone could make a parody tune titled "Crapping in the Street" based on "Dancing in the Street" by Martha and the Vandellas.