Its not Antifa, its the people behind Antifa. These aren't useful idiots, these are professionals hired to do this.
As an example, two banks in La Mesa, Komifornia burned to the ground.
These were modern banks made of steel studs and big open lobbies.
As in, NOTHING to burn.
There was nothing there that spark, a Molotov, could set on fire.
So, someone brought in enough incendiaries to light these two buildings up when the riots happened later that night.