Personally, I've never had good luck with polishing housings and keeping them clear. It always turns into a "polish every few months" activity.
Plenty of cars have just generally crap headlights. Depending on the housings, there are a few options. If they take H4 bulbs and the housings can handle some extra heat (and have a decent beam pattern), you can upgrade the wiring and run higher wattage bulbs. For high beams that use a 9005 bulb, swap to a 9011 HIR bulb with slightly modified tabs so it fits. They're optically compatible in high beam use and the 9011 is a bit brighter.
Other options are a projector retrofit (generally the best route to good low beams). And you can always add driving lights to supplement high beams.
I'm no fan of stock headlights in most cars. At this point, SWMBO's Prius is the only thing in our fleet with stock lights, and that's only because it's on the chopping block for replacement (so not worth upgrading even though the headlights are awful).
The E38 has 9011s in the high beam spots, and I also swapped the stock Bosch low beam projectors for bi-xenon ones (currently it has Mini H1 7.0s in there, but I'd love to upgrade to the Micro D2S 5.0 that came out later on).
The Jeep has the glass lens Euro housings (much better beam pattern) with 100/80 watt H4 bulbs in there, which gives pretty good low beams. And then a pair of driving pattern Hella 4000s on the bumper with 100w bulbs, and a pair of IPF 968s with 100w bulbs outboard of those and aimed outward slightly to give more light along the sides of the road for wildlife. The lights on the bumper all trigger with the high beams, so the high beam switch delivers 600 watts of halogen in old school form.
In my mind, low beams definitely reach a point of "good enough" where more light isn't really useful, a good beam pattern and wide spread matters more. For high beams, there's no such thing as too much, provided the light goes somewhere useful. The only downside of really good high beams is that road signs are often too reflective and can be downright blinding.
Another note on the low vs high beams thing: high beams aren't necessarily brighter than low beams, and on many stock single bulb headlight setups, they're only slightly brighter at best. The biggest difference between what makes a low vs high beam is the beam pattern (and that's why there's a limit to how much light is useful for a low beam, as it only has a certain area to fill, so more light doesn't help you see further).