LED headlights wash out turn signals

Yesterday I was at a stop sign. The car opposite me had blinding LED headlights. We arrived at about the same time and it looked like the other car was going straight, so we both entered the intersection. The other car turned left and I slammed the brakes. When the headlight weren't in my eyes, I could see they had their left turn signal blinking.

No collision, not even close. Why have turn signals if nobody can see them?