Point of fact, they were not blocking traffic but rather walking down the street with very little traffic at all. They were crossing on a red light, which is legal, when a car drove against the light toward them.
The so-called dangerous people did no damage, nor did they actually trespass on their property. They certainly trespassed on private property, sure, but they were not actually on the property of the two people who drew their guns. So, it wasn't "their" property, exactly. It was the neighborhood's shared property.
My argument stems from the fact that both parties drew their guns. Leading some to make the very reasonable claim that if you point a gun at someone, expect to be shot if you're not going to use it. So, either the couple put themselves in more danger by "defending" themselves OR Garrett Foster was shot for "defending" himself.
Your analogy is quite flawed in two very important respects. First, cars can be used as a lethal weapon. This is why police officers are perfectly willing and legally authorized to open fire on suspects fleeing in vehicles. They don't even have to claim that the car is "coming at them" but rather that the suspect was endangering the lives of other civilians, whether present or not. By that same argument, if you approach a crowd with only the intention to mow them down, then armed protesters have the same right to defend themselves. Especially, if that car was crossing against the light, which it was.