I mean, in the short term (50-100 years), yes it is. Unless people start dying at a younger age, there’s going to be a lot of orphaned seniors, which isn’t good. We won’t really see the benefits of a declining birthrate in our lifetimes, but we will see numerous negatives.
In the long term, it’s probably more nessecary then “not bad,” but again, you don’t want to be the one of the people living during the population collapse.
It’s addictive, it’s marketed well, people are uninformed about how awful it is for them, and think prepping healthy meals is a lot harder than it is.