I guess all people can be assholes so no doubt there are bad royal mail postmen. However my experience is royal mail have been the exception. They knock and wait.
Amazon however, especially since COVID, dump and run. This hasn't been the norm in the UK but now they do it all the time.
It won't be long before we get porch pirates like in the US.
I just read that the US blocked this. https://lemmy.world/post/20190872
Now I'm confused.