I absolutely know Antifa exists because Rose City Antifa shut down I5 in Vancouver to protest some drug dealer being shot and I saw it. They had a drum corps, flags, banners, common clothing, walkie talkies and the rioters were organized via these leaders on the walkie talkies in a military like manner. Antifa is not a monolithic entity but a highly decentralized network of autonomous groups and individuals operating without a central leadership, formal hierarchy, or unified command structure. They do have leaders who organize the riots and protests, they operate from the shadows to minimize risks of infiltration by law enforcement or adversaries, and members frequently conceal their involvement to avoid doxxing or legal repercussions. Due to its decentralized and non-hierarchical design, Antifa's financing is opaque and lacks a centralized budget or formal accounting, making comprehensive tracking difficult. However it is a decentralized organization, although it has no president, it is organized, it does have leaders, it does have financing and it does function as a group.

Here is the Portland Branch of Antifa, looks like an organization to me:

https://rosecityantifa.org/