bruneep- they’re lighter for a given strength, and they make you more attractive to the opposite sex. On the negative side, cackhanded people often manage to damage them by massively overtightening the clamps, stem etc which can cause them to fail. And abrasion damage can be an issue with a badly set up bike.
As far as strength goes… depends how much you want to swallow a marketing line but the Easton Monkeylite DHs were allegedly too strong for the stress tester that they used on their alu bars, they had to build a new machine to break them… And the current Haven is supposedly just as strong despite weighing as much as a wet far.
Some people think they make a difference to trail feel. I have no idea if they do or not.