Cryptocurrency was brought into being for a number of reasons. It's a scam with national security implications.
1. Tax evasion
https://www.voanews.com/a/nigeria-sues-cryptocurrency-firm-binance-for-tax-evasion-/7542290.html
https://www.washingtonpost.com/dc-md-va/2024/06/03/bitcoin-investor-michael-saylor-dc-tax-evasion/
2. Money laundering
https://www.economist.com/by-invitation/2024/06/10/digital-finance-is-a-money-launderers-dream-argues-an-author
https://www.icij.org/investigations/fincen-files/new-us-treasury-strategy-targets-crypto-scams-and-real-estate-money-laundering/
3. Supplant the US dollar as the global reserve currency
https://www.bloomberg.com/news/articles/2024-02-15/fed-s-waller-says-dollar-to-withstand-threats-from-china-crypto
4. Threat funding
https://www.bushcenter.org/publications/the-danger-of-cryptocurrency-in-terrorist-financing
https://www.cbc.ca/news/canada/ottawa/freedom-convoy-cryptocurrency-asset-seizure-1.6389601
https://www.unodc.org/roseap/en/2024/casinos-casinos-cryptocurrency-underground-banking/story.html
5. Straw donor schemes
https://fortune.com/crypto/2023/10/16/ftx-straw-donor-sam-bankman-fried-nishad-singh/