It's really not that simple. Some of them are, some of them aren't.
Virtually every owner of a '93-'00 Chrysler product who pays any
attention at all to headlamp performance pines for the "performance" of
the $9 sealed beams on his '60s-'80s cars. And as a concept,
sealed-beam construction in standardized form factors makes a great
deal of sense for automotive headlamps. The _implementation_ we were
stuck with for so many years was poor, but there's nothing about
sealed-beam construction, per se, that locks one into poor headlamp
performance. There are plenty of bad replaceable-bulb lights, too.
There are even bad "Xenon" HID lights. Good lights are better than bad
lights; there's too much room in the US headlamp standard for various
kinds of bad lights.



There's nothing wrong with the sealed beam construction itself, but the
classic DOT headlamps *suck*. Installing quality OEM E-code headlamps on
my European car was the best thing I ever did to it. People who ride
with me often comment at how good the headlights are and they're usually
shocked when I flip on the high beams. The original sealed beams were
downright dangerous, I was overdriving my headlights going 5 under the
speed limit on a dark highway, yet they still produced more glare to
oncoming traffic than what I have now.