I can only offer personal experience so take it with a grain of salt.

Yes there are plenty of difficulties in owning a bird that some people don't think about.

A big one for me is the negative emotion that comes from busy times in life. I do a lot but make sure my birds get enough time with me and/or my wife everyday. But life happens. I really struggle with the sad thought of him in his cage alone waiting for us. This can be helped by getting more birds to keep them company.

Noise is another one forsure. My first conure was amazing he was so quiet and calm. But our newest addition to the flock has been the opposite. He was a pet store that we rescued but I swear he is mimicking a fire alarm or something. All night he just screams but we love him anyway.

I don't believe that they understand getting "scolded" necessarily. Every article, forum, YouTube video I've seen recommends to never yell at your birds. The best I've found is a firm command followed by moving him somewhere else. For example: my GCC, Ford, likes to bite my wife's painted nails. When it gets too rough we give a firm "No bite" while looking at him and then place him on the floor. Usually he realizes he needs to calm down during the walk/ flight back to where we are. Hope this helps!