What causes blackheads?

I'm contacting you because I keep getting blackheads, mainly on my nose and navel zone, and I want to know the exact cause of them. I wash my face thoroughly and use sebum control products, but I'm worried that the blackheads aren't just due to cleansing. I've heard that blackheads are caused by a combination of factors, such as excessive sebum secretion, enlarged pores, and dead skin cell accumulation. I'd like to know which cause has the biggest impact on me. I'm also curious whether using extractions or nose packs makes blackheads worse, and whether dermatological treatment can fundamentally improve the cause of blackheads. If you have any recommendations for lasers, peeling, or management programs that are suitable for the cause of blackheads, please let me know. Also, please provide information on daily care methods to reduce recurrence.