I suggest people read about the 4 stages of demographic: https://www.economicsdiscussion.net/economic-development/4-main-stages-of-demographic-transition-economic-development/19129

Developped countries are in the 4th stage, even possibly actually reaching a new 5th state. Basically, it goes like this:

• 1: Low quality of life means high mortality. Which means adults were having lot of children, because they knew only a handful of them would actually survive.
• 2: QoL improves, mortality decreases. However, people are still "used to" making lots of children. That's the beginning of population explosion.
• 3: People are finally getting used to it: Natality starts to decrease, but mortality went so low, population is still rapidly growing.
• 4: Both mortality and natality are gettting very low, population stagnates.
• 5? (technically not in the 4 demographic stages, but still happening): What we're seeing right now, women are actually having less than 2 children, which means population is actually decreasing. For pop stagnation, we need ~2.1 children per women.

The only reason US/Europe pop is not technically decreasing, is because of immigration.

Look up the fertility rate per woman per country, you'll see it's quite alarming https://en.wikipedia.org/wiki/List_of_sovereign_states_and_dependencies_by_total_fertility_rate

Most developed countries are at very low rate, like < 1.5. When you think about it, it's quite terrifying actually. It basically means we're losing 1/4 of people every single generation (4 parents have 3 children total, 25% loss). Not just that, this is happening in almost every country in the world. Pop collapse can be very real.

The only "overpopulation" happening is 100% because of developping countries, which are still in phase 2 or 3. In a few generations, they will either see mass mortality (back to phase 1), or go into phase 4 and stagnates.