There are fewer places than you think with no light. I remember watching many moth's flying around street lights and my porch light. Haven't seen that for years now.
I live about 10-15 miles from the nearest decent-sized town, and I've seen this change. Tons of people moving into these areas, and the first thing they do is install (or pay the electric coop to install) outdoor lighting. As per one of the other posters, it's almost always that obnoxious 6000K+ color lighting that's blue-white enough to hurt your eyes. And I used to whine about the sodium lamps...
My state has light pollution laws under the Dark Skies Act. Good luck getting it enforced since most of the astronomers who lived here have either moved or died.
Bright outdoor lights used to be expensive, and installing/running them unnecessarily would have a significant impact on power bills. Not any more.
(That said, the "insect apocalypse" began long before LEDs were a thing...)
This is exactly it. Leaving half a dozen LEDs on all night long is far cheaper than doing the same with traditional lighting. Then you have those stupid strings of warm white LEDs that I assume are intended to look like candles and are apparently all the rage right now. To say nothing of the couple of houses across the valley that have motion lights--at the end of their driveway--activated either by a brisk breeze or errant skunk.
What worries me isn't so much whether light pollution is contributing to mass insect deaths (that seems debatable); it's that light pollution is getting so much worse that appreciating the night sky is going to become increasingly harder for more and more of the population.
GP has a good point, insect can evolve very quickly. And it is probably much easier evolutionary to adapt to light pollution (it's a software change, after all) than to insecticide (which affects cell chemistry) or complete change in habitat due to its destruction or climate change.