I couldn't agree more.
And I can only reiterate, with my initial comment I was not attacking you personally or trying to guilt you into doing something. I also don't like when people do that. In fact, it wasn't even that much about saving water in the shower. It is just this blocking attitude of: I don't do it, others should start first without even thinking about it, that you can often read in these threads which bugged me at first.
By your comments you showed that you actually thought about it and came to the conclusion that the impact is little and there are more important topics you want to address, which is a totally fair point.
I have never used an ESP but as far as I can tell, you are right. There is no component involved for the 5V. Some boards have a diode and a fuse between VBUS (5V USB) and the 5V rail on the board, but that is not the case for the board in your picture.
The black component with "512" is just a pull-down resistor for one of the CC lines of the USB connector. This should not get particularly warm.
The brownish thing is the input capacitor of the voltage regulator. It can get a little warm due to ripple currents, but I wouldn't expect a lot of heat.
Are you sure it is not the black 5-pin voltage regulator for the ESP? As far as I know those ESPs can be a bit power hungry depending on what you have enabled (e.g. WiFi).
Maybe you can check the temperature without your LED matrix connected and see if it is hot as well.