I think that it's undeniably sub-par work. Unfortunately, no one can tell you with any certainty how long that will last before you have issues. My Dad poured a patio for a customer 40+ years ago and had the top washed off in a huge down pour, took a power trowel to the patio, broomed it, and it still looks pretty good to this day. I've had jobs that snapped off from the heat and I tore them out 2 years later because they spalled in the winter. No one knows how long they will last.
One concern that no one brought up yet: Is the stoop with the extra step sitting on a foundation? If so, the sidewalk should have been separated with some form of expansion material. And the connecting sidewalk certainly should have had at least one more control joint, it's far too long and is most likely to crack..........