I don't know. I've had this thing a little while now, and it doesn't sit in a drawer or a trunk. It gets used daily when the dog goes out at night. It's got quite a few hours on it thus far, and it still shines as bright as the day I bought it. In short, the thing does what I bought it to do.
My only worry about multiple cells is leakage. Todays batteries seem far more prone to leakage than the Alkaline batteries that were on the market 20 years ago. I don't know what they changed, but I've had brand new Ray-O-Vac's leak right in the box in as little as 4 months. That's ridiculous.
Back in the 80's I had Duracell's go 20 years with some swelling, but zero leaks. Cost is pretty much irrelevant. I have a 6 "D" Cell incandescent Maglite that at least 25 years old. A 6 pack of "D" Cell Alkaline batteries is close to $20.00.
I can get a 12 pack of AA Lithium Eveready's for just about the same, or just a couple of bucks more. And Lithium's rarely leak... At least not yet, until they find a way to make them. And I'm sure they will. But battery cost is pretty much tit for tat.
Which one will last longer? You tell me. But I'll say this. That Harbor Freight LED outshines the old Maglite 10 fold. And it has both a high and low setting, as well as a SOS strobe setting. The Maglite is either OFF or ON.... And keep in mind that a 6 "D" Cell LED Maglite that compares to it runs over $110.00. Or almost triple.
If you like the light, and it works for you, that's fine. Nothing wrong with that.
But for what you paid for it, and what it will cost to feed it, you could have a light that would eclipse it in performance, value, and quality, while at the same time being much better in design, simpler in construction, and more versatile in function, including things like what you would like to illuumate (near vs far), in what color, and how accurately objects should be rendered.
Flashlight technology has advanced in leaps and bounds since the Rayovacs, Evereadys, etc. ruled, and while the Maglites were good quality, their performance was mediocre even when they were the state-of-the-art.
One could ignore whatever this guy is saying (which on YT, is advisable a lot of the time), and just look at the pictures of the beamshots, which are worth a thousand words.
A good modern LED flashlight is not all that expensive, and those who get introduced to them are often astonished at what a "real" light can do, and fall into that rabbit hole.