The problem with your viewpoint is that it's little more than a thought experiment. Realistically, you will never get all 8 billion people who inhabit this planet to make the necessary lifestyle changes needed to combat climate change.

https://www.wri.org/insights/4-charts-explain-greenhouse-gas-emissions-countries-and-sectors

This one throws has some good figures: https://www.epa.gov/ghgemissions/global-greenhouse-gas-overview

Sources we could attribute to individuals:

• Transportation (15%): including public transport
• Buildings (6%): this includes energy usage and waste

In total, 21%. Even if we said that's still a 21% we could do something about, besides switching to a green energy provider and using an EV instead of diesel cars (which is a good move though sourcing the Lithium-Ion batteries these EVs is a big problem in and of itself), what else is there for the average Joe to do? Companies and governments should give individuals the option to lead a sustainable lifestyle. At the moment, the reality is the options simply do not exist or are so expensive that are out of reach for the vast majority of consumers.

On the other hand, we have industrial and public usage...

• Electricity and heat production (non-residential), which was (as of 2019) the leading source of global carbon emissions, accounting for 34% of the total emissions.
• Industry (24%)
• Agriculture, forestry, etc. (22%)

That's a staggering 80% altogether.

You ever heard of the Pareto principle? It says that 80% of the consequences come from 20% of the causes. In this case, 80% of the emissions come from a minority of people (industry, corporations, etc.).