Why 24V LED strip is better than 12V? Why you can’t connect long LED strips to the power supply?

Introduction

I noticed that my LED strip samples have different base thicknesses. Most samples are thin and bend easily; some are thick and hold their shape well after bending. I found only one metal in the strip base. The copper conductors transmit the power along the tape to all the LEDs. I thought that the inner conductors' different thicknesses meant different electrical characteristics. Aha! There's a lot to study here!

Next, I'm talking about regular strips no more than 1/2" wide with constant voltage.

Why are the conductors in the strip important? Many types of LED strips are high power to generate a lot of light (shine brightly). The more power, the more current. The conductors must be thicker and wider (cross-sectional area) to allow more current flow. Power losses will appear in the conductor, and that conductor will heat up if that area is not large enough. So less electricity will reach the far-end LEDs, and they will shine less. If the LEDs emit light with different intensities depending on their location — it is a bad strip.

So. The current through LED strip conductors depends on the power of that strip and can be up to 0.5 Amps for each foot of strip (8 Amps (!!) for a 16-foot (5 meters) strip).

My samples in the power consumption measurement experiment :