it is a fairly common and substantiated geopolitical view that organized crime and authoritarian regimes have co-existing links.

irregularwarfarecenter.org - Transnational organized crime in the gray zone the authoritarian iw toolbox and strategic competition

e.g., at various times, it is believed the entirety of the N.Korea economy hinged on illegal activities.

more broadly, these regimes decide what type of local organized crime is tolerated (primarily to auth. benefit) and international crime is ignored (primarily to competing nations' detriment).
regarding specifically chinese chemical companies, they have many global customers and the CCP clearly knows and supports the part of their trade into mexico is going towards cartel drug mfg. this is why the biden admin attempts to get CCP cooperation, but ultimately can only hit these companies with sanctions unilaterally. likewise on the tolerance and participation of money laundering.

i suggest watching the entire financial times video.