The Trijicon RMR has a battery life of 4+ YEARS on the middle setting (4 of 8). I run my dot a little brighter then that (6 of 8). Ive never had a dead battery. I change batteries once a year and could prob go every 2 years, but batteries are cheap and im counting on the gun to save my or someone else's life. A little maintenance is a small price to pay.
So, on my Birthday i have a battery swap session. All my longguns and handguns with dots on em get replaced.
In addition, most people that run red dots have some type of iron sight back up. My red dot equipped pistols have suppressor height sights that can be seen thru the window of the red dot. So, even if the dot somehow fails, i just shoot with the irons.
Heck, if the dot fails at conversational distances (less then 5 yards) just see his chest thru the window and go... the dot only allows faster PRECISION work. You should have built the muscle memory (god, i hate that phrase, but its widely understood) to achieve good hits at 3yards WITHOUT needing the dot as reference. In fact, you should train with the dot off and “shoot thru the tube” at least enough to be comfortable with the concept.
If changing a battery once a year is too strenuous, then dont put a dot on. If $600 is too expensive, then dont put a dot on. If you dont want to spend the cash to have your slide milled...well, you get the point.
Dots are not for everyone. Those of us that use a gun seriously and are willing to put in the time to understand it strengths and weaknesses, find them useful. Head shots at 20-25 are all the sudden not that hard to make. COM hits at 100 plus are not difficult. Up close they only slow you down if you let them. Like i said above, chest in window...press the trigger. Oh CRAP...partial head at 7...hold the dot and press.
Just like the Rifle, better sighting systems are becoming standard. The ol’ front sight blade in the rear sight notch that has been around for 300years(?), is no longer the cutting edge.
But, maybe some folks are still happy with dial-up modems