Could be an effect, but saying they "worked" presumes a goal. Tactically, one might say they worked.
Thanks for the coverage of this subject, but I have yet to see any clearly state the goal of the sanctions, which leaves the matter open to much wild speculation. Perhaps the underlying rationale hasn't been well-publicized, but some reporters seem to have learned more about that.
I hope further articles can delve more into the rationale or objectives of these sanctions, based on whatever the Biden administration has actually said, or what other well-placed sources can reveal.