I drove for DoorDash and Amazon Flex part time a couple of years and noticed that at gated communities there was a gate stuck open at least 50% of the time. And if there wasn't, at any decently large community I'd just wait until the next resident came by and opened it for me - assuming it wasnt a place I already knew the code or someone had written it on the visitor box itself.
Also, those parcel pending package dropoff places are another area where people would write down the master codes to get in to deliver packages. Its crazy just how insecure all of these 'secure' places are.