The light that died from rain through the switch was a niterider. Filled up with water. A sunbike 150 lumen flashing front light did okay in the rain for 2 years but the battery prong finally corroded off.
I have had a catseye front light for about a year. Lives in a peanut butter jar in the bag, so no real test of rain resistance. Last night it was under a bunch of christmas presents in the bag so I rode home in the dusk with no front light. The trouble with the catseye, it will not charge most of the time. Only if nearly dead. So if I take a 3.7 hour commute to my summer camp the battery runs out about the time I get out in the country where the houses are 500 yards from the road and 1/4 mile apart.
Those $190 lights people are touting must be really nice. I have had 2 lights stolen from my bike while shopping or doing volunteer work. The Garmin Varia, while useless as a warning device, is a really good taillight that the mount is too weird for the thieves to figure out. Going on 4 year old now. If I believed I was in danger every time the Varia warned of a vehicle on the Interstate through a metal fence, or traveling at 90 degrees to my path behind me, or mowing or tending a crop out in a field, I would stay home and plug up my arteries with cholesterol.
For backup rear I use a brightz red or pink flashing light, screwed under a plastic flange to keep the rain off. On switch lasts about 3 years. Costs $12 when you can get them; the Meijer store always has the blue ones. I lost a brightz mounted with the included tie-wraps that was cut off with knife.
Bought my first cygolight rear light last month, a 50. Is going to be a nuisance to mount it; strap to seatpost location will be invisible if I wear a jacket or vest.
As far as the invisible riders, 90% of bike riders in my neighborhood wear black, dark grey or camoflage. No lights. Ride against the traffic mostly, and never slow down at stop signs or traffic signals. This includes the guys who have converted a beater frame with a stinko gasoline motor. I wear a yellow logo helmet and a yellow-green ANSI-2 construction vest with reflective stripes. If anybody is looking I stop at traffic control. Not, not.