It’s impressive how quickly the WWW became mainstream, given how few people had internet access back then. Bitcoin is now 16 years old but compared to the WWW in 2008 is hardly used on a daily basis.
Money in mailed in envelopes. Western Union. Prepaid credit cards. Stolen credit cards. Bank transfer to a legitimate business that funnels it to their drug empire.
For agent to agent payments, Bitcoin/Ethereum could be quite useful now, as traditional payment protocols and banks are not likely to provide decent APIs any time soon.