>However, the political climate around 1970s was more like population would create large scale food shortages, famines, and without interventions, population would keep on growing forever.
All of those things came to be - and we're on track for food shortages and famines too with the environmental crisis.
The latter has the qualifier "without interventions". The interventions just happened (widespread acceptance of abortion, "1 child per family", increased neoliberalization attack leading to less people being able to afford to start a family, cultural changes around marrying, loneliness epidemic, etc).
We are not on track for famines due to lack of food production. It's been solved.
There is more trade then ever people are richer then ever and therefore less likely to have kids. 1 child per family law was a gross violation of human rights that likely did not significantly change the birth rate compared to other countries