That's pretty bad. Whoever built that either watched a YouTube video and took shortcuts or it was someone who helped someone build a deck once and then tried to do it on their own. My guess is that this was a house flipper who did this or paid the lowest bidder to build it. Anything 10x10 or larger usually needs to be permitted nd inspected. There is a house on the block of one of my rentals that was bought by a house flipper had the attic converted to a bedroom and the basement finished into a bonus room with kitchenette and then put back on the market. Also new HVAC system. Absolutely no permits or inspections. The only way they'll save their butts is if someone comes in from out-of-state and pays cash with no home inspection. The seller can still be sued years later if they have problems from poor workmanship and they do some digging at the city permit office.