Always seem to be more people sitting on the blocks than on the proper seats, probably because they are actually more comfortable than the real thing. Nice and smooth. No splinters.
And so far (frantic grab for something wooden), they have not been hit by the blight of modern life, graffiti. Or perhaps they are just easy to clean. Or maybe they are being watched over by those who were evidently not out chasing inconsiderate animal owners ‘with vigour’.