@Desert Captain
Why? For me it was about my converter's fan. In a word: Amps.
I had 9 of the below (1141) double pancake lights in my MH. I replaced then with
Thin-Lite LED double pancake lights.

If I turned 3 of the 1141 double pancakes lights on (both side - 6 bulbs) the converter's fan would start up after about 15 minutes. The converter was OK when 4 bulbs were lit. With the LED double pancake lights I can have every single one turned on (both sides) without the converter fan coming on.
Also, In the bathroom I have a 14 speed Fantastic Vent that shares 12V with the ceiling light (double pancake). When it was an 1141 pancake light the fan would slow down when I turned the light on (even just 1 bulb). With the LED pancake light the fan does not slow down - even with both sides lit.
For me I wanted better lights with better on/off switches than on the one pictured above - AND - I didn't want to overtax my Parallax 7345.