In the early 1970's I bought a pair of 7 or 8" Marchal auxiliary lights, deep form, gray paint. Bolted them into my car for rally and backroad use. And I changed out the original bulbs for thoroughly illegal 100W bulbs, one each. Around 1990 they were stolen with (on) another car and I haven't seen them since. But if you come across a set painted bright red over the gray--that's them.
Anyway, the car I'm driving now has bi-xenon factory lights. Nice BRIGHT lights. But unless my memory has really faded, the grand new factory bi-xenons still don't light up a stop sign a mile down the road, the way the Marchal's did. Maybe some third party technology does and it is simply that the car makers need to stay within the legal limits...as I recall, at the time, each of my 100W Marchal's was well in excess of the total legal limit for highway use.
And of course the quality of the housing, the lens, the waterproofing, was well in excess of any aftermarket lights I've seen today. They might have been $100-150 back then, complete with the extra 100W bulbs.
What are rally drivers using today? Surely not all vintage lighting?
AFAIK filament bulbs are still very much cost effective for occasional users.