Look at the market that bicycle lights are designed for. High power lights in the outputs you are talking about are still aimed at the off-road rider but not at the commuter. Off-road a cut-off or a highly shaped beam wouldn't be of much use. You want all kinds of light sprayed all over the trail so that you can see obstacles that you need to negotiate.

3000 lumens is about what a car puts out on two beams. Motorists have to deal with that kind of light coming at them all the time. Although some beams have a very tight cutoff, that's not the case universally. SAE rules in the US even call for a significant amount of upward spillage to illuminate street signs. And there are enough older cars without any kind of cutoff on them that bicycle lights shouldn't be all that much of a problem.

Additionally, look at where we ride as cyclists. We don't spend a whole lot of time over next to the center line. We are usually outside of the right wheel track (US) by 2 to 3 feet. Any stray light sprayed out isn't likely to interfere with motorist come at us nor, for that matter, motorists that have passed us. A approaching motorist is going to see more sideways light much closer from an on-coming motorist within 3 feet of his driving position than from a bicyclists that is located 10 to 15 feet further away. Even with a 35 degree beam, you won't even get close to putting enough light onto the other side of the road to cause an issue.

Personally, I rather have lights that are an issue for motor traffic since those get seen (given our road location). The bicycle market is far too filled with 'polite' lights, aka 'be seen lights', that are absolutely inadequate for what they are being used for.