Nigerian here. The initiative to link SIMs with biometrics kicked off after that highly-publicized series of ENDSARS protests protesting corruption, police brutality. The protests were eye-opening for the government (that popular resistance could be organised without people ever meeting in person) so they want better tools to link you finances, etc. to your communications.

Roughly three weeks ago, telcos started disconnecting numbers that haven't been linked with biometrics & I've been barred from making calls since then.