While I agree that simply focusing on the method used is missing the bigger picture, it can have benefits. In England & Wales, changing domestic gas formulation dropped the overall suicide rate [1], so there is a precedent for positive effects from removing easy access. While this should certainly not be the only measure, it can be accomplished quite a bit more quickly and easily than changing both the university entrance process as well as the parenting culture. But I would consider it at-best to be a stopgap measure.

[1] https://www.journals.uchicago.edu/doi/abs/10.1086/449144?jou...