> Analysts estimate that underground economic transactions account for one-third (33%!) of the total economy in developing countries and slightly more than 10% of the total economy in developed countries. [0]
On the Bitcoin blockchain it may be around 19% (approximately USD $380bn in yearly transactions on Bitcoin [1], $72bn of which may be illegal [2])
So it's hard to say which "monetary system" is doing better in that regard. Of course, I would argue that cryptocurrencies are still in the experimental phase, trying to figure out where they are going and how.
[0] https://www.investopedia.com/articles/markets-economy/062216... [1] https://www.blockchain.com/charts/estimated-transaction-volu... [2] https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3102645