Unfortunately we seem to have entered an age of 'lighting wars', with everybody wanting brighter and brighter lights just to keep up with, and compensate for the lights of others. I agree, for some at least - self included, the amount of glare makes night driving quite unpleasant.
Even cyclists have joined in, with powerful LED torches on their handlebars, pointed straight in the eyes of car drivers. Apparently it makes them feel safer, being noticed. Though I'd not feel safe at all on a bike faced by car drivers suffering temporary blindness.
Most of it is, if I understand right illegal, if only police had man-power to enforce and prosecute.
Aftermarket Xenon HIDs are illegal for all manor of reasons including as stated absence of self-levelling, but also because the reflector, unless replaced, is the wrong shape and only approved for conventional bulbs. IIRC Even factory-fit HIDs are technically not really legal under UK Construction and Use regulations, but we have to tolerate them as European Type Approval effectively takes precedence.
My view has always been, those who feel the need for for brighter headlamps, should (a) visit the optician for an eye test - new glasses can work wonders, (b) replace the existing bulbs as they can degrade, (c) avoid driving at night.