I would still call it one of the epicenters. Yes, many venues that were previously only multlipliers like some prolific streamers / Youtubers / TikTok channels have grown and cultivated their own distinct subcommunities which form new epicenters.

However, from what I can see /pol/ still serves as significant breeding ground where people deeply committed to their views can get together in a "mask-off" manner without fear of moderation, while they have to be more "mask-on" on platforms that are more dissemination-focused like Youtube.