Totally agree. We should have <1B people living like kings, not 10B people living like peasants. A lot of environmentally unsustainable things become perfectly sustainable if there are fewer people on the planet. Like, we shouldn't have to be worried about the impact of beef production or overfishing - the planet should be able to sustain the number of humans that want to eat those things. At 8-10B it obviously can't.

The fact the nearest store is 20 blocks away is a consequence of bad urban planning

Amputation doesn't cure a systemic disease. Very little has to change about most people's status of living in order for the vast majority of people to live comfortably without being forced into buying plastic, driving everywhere, etc. These are bad planning and poor oversight issues that have nothing to do with numbers of people in a population.

The majority of the remedy that would solve the issue long-term is opportunities and competition in green tech (which is being held back in favour of propping up a few fossil fuel giants), refusing to excuse wasteful and damaging industry practices, fugitive emissions, wastes of resources, etc. The ones who would be most likely to see significant change to their lives are the ones who are also individually wasting the most resources (with private jets, yachts, powering multiple homes, etc.)

But sure, give that small minority of super-wasteful people an excuse to waste even more and kill people off (since we don't have time for natural causes or accidental deaths to make a difference) to prop up their lifestyle.