Alkalines simply don't cut it for high drain applications. Such as "max" mode for most flashlights: They can't deliver the currents involved. The light will work, but at much lower intensity than you've bargained for.

Alkalines are OK if your needs are more modest. Say, your flashlight at low or medium modes. I don't like alkalines for several reasons, but that doesn't mean they won't work within some constraints (not too low temperatures, not in high current applications).

Izzy, I'm surprised that eneloops don't live up to your expectations. I'm quite happy with eneloops and similar low self discharge batteries by other vendors.

That being said, disposable (single use) lithium has a lot going for them. In particular in the "emergency only" scenario.