Titanium has no inherent advantages other than its anti-corrosive properties. It is pretty, though - and weighs less than stainless steel.
Well I've seen a number of SS lights over the years, most a lot larger than your average LED light today. Not that common, but not rare either. So weight can't be much of an issue. Nor thermal conduction - iirc, SS has even worse thermal conductivity than titanium or most types of brass, and flashlights have been made successfully out of all those materials.
If you try to find prices of titanium metal, all I can find are various shapes & alloys, most with a price in 6-20 US$ / pound range. Maybe I'm missing something here, but it seems to me that price of the base metal isn't much of a problem. I can understand the cost of "difficult to machine" though...
I have only 1 Ti light so far, use and love it. So another way of phrasing above quote is: there are no (big) inherent
disadvantages to using titanium, other than the cost of machining it. And it looks good. With 3D printing moving into metal territory as we speak (!), perhaps those machining costs will go down for titanium too. :thinking:
But given things as they are,
no way titanium will beat aluminium for "lowest cost, good enough" uses.