There are, broadly, four routes to getting people to stop using dangerous consumer products:
- Public education: This is easiest, but not particularly effective. Doctors, and more recently governments, have been telling people to eat less sugar for about a century; meanwhile, in most places, the level of sugar consumption has only increased.
- Taxes/levies: This is thought to be somewhat effective (in particular it seems to have worked in many places for tobacco to some extent), and it has the great advantage that it's _easy to do_; governments typically have a lot of latitude over what they tax and it's quite difficult for the industry to resist through legal means (they can still lobby, of course).
- Ban or restrict advertising: This seems to have been effective for tobacco and maybe alcohol, but certainly in Britain it's currently seen as a bit culture war-y (Sadiq Khan banned ads for unhealthy food on TfL, apparently with some promising results, but the right-wing media had a complete nervous breakdown) and is open to legal challenges. Some other countries, with different political environments, are in the process of doing this for certain problem food products.
- Ban the product: This is practically impossible, even for products which are known to be extremely harmful like tobacco. Just a political death sentence, not worth pursuing.
Given the above, they probably did about the best they could.
- Public education: This is easiest, but not particularly effective. Doctors, and more recently governments, have been telling people to eat less sugar for about a century; meanwhile, in most places, the level of sugar consumption has only increased.
- Taxes/levies: This is thought to be somewhat effective (in particular it seems to have worked in many places for tobacco to some extent), and it has the great advantage that it's _easy to do_; governments typically have a lot of latitude over what they tax and it's quite difficult for the industry to resist through legal means (they can still lobby, of course).
- Ban or restrict advertising: This seems to have been effective for tobacco and maybe alcohol, but certainly in Britain it's currently seen as a bit culture war-y (Sadiq Khan banned ads for unhealthy food on TfL, apparently with some promising results, but the right-wing media had a complete nervous breakdown) and is open to legal challenges. Some other countries, with different political environments, are in the process of doing this for certain problem food products.
- Ban the product: This is practically impossible, even for products which are known to be extremely harmful like tobacco. Just a political death sentence, not worth pursuing.
Given the above, they probably did about the best they could.