I actually agree with the OP. There are lots of little things going on when you travel around the city, much like in RDR2.
I've stumbled on random shakedowns by gang members, a block party with booming stereos and gangers dancing with regular citizens, a police blockade and various minor gang-on-gang fights. None of them quest related, but just little scenes you come across that give life to the city.
I also agree with the people saying NPCs outside of such events are lifeless. They are part of the scenery though and I don't quite know what people are expecting. 90% of NPCs in RDR2 have no interaction either, nor do they have any sort of daily routine apart from standing still in different places depending on the time of day.
Also, it is a major issue how static the police are currently, but based on the recent investor call this seems like CDPR knows this is an issue and intend on doing something about it.