LVP is important in lights with boost drivers, such as Zebralights. Otherwise, the light could easily drain the battery far too low, without you noticing.
In lights with XPL/XML/XPG emitters that generally require buck drivers, you probably don't even need LVP. I find that those lights of mine without LVP will dim well before the voltage gets below 3.0v. They usually shut off completely below 3.0v. The LED just won't work when the voltage gets too low. However, I'm not certain if the driver shuts off completely, so it's possible the voltage continues to drop, but it doesn't appear to drop very fast.
Finally, LVP can be kind of useless in multi-cell lights. One cell could be weak, but the entire pack still above a decent voltage.
Personally, I prefer lights that warn me when the battery is starting to get low (switch indicator or some kind of flashing), well before any LVP would be needed.