I think true acts of kindness are difficult to achieve because something that you might find "kind", I might not, and vice versa. I think if you truly want to make people happy and do nice things for them you need to know them, their situation, what they're doing well with, what they're struggling with. Being tricked into holding random flowers wouldn't have made my day.

True acts of random kindness are rare only because most people aren't in need of random help that often. There is a wide range of things that would fall under the umbrella of 'just being polite' that are more expected social behavior than actual kindness.

And you can be kind to people that aren't in dire straights or in need.

However he did pay for groceries for a few randos, so that completely balances it out.