This is like the "both sides" argument in politics.

It resonates with people and encourages apathy supporting the status quo.

Its true that the actions of an individual aren't very impactful. Its also true that large corporations are responsible for the vast majority of the problem.

However, if no one bought products from those companies, or owned their shares, then they would exist.

While "no one" is not possible, what if everyone just used 5% less, or 5% of people switched to an "ethical" 401k / pension funds that didn't invest in these companies.

We dont need a few people doing climate mitigation perfectly, we need everyone doing climate mitigation imperfectly.

It sounds like such a small change, yet we're unable to achieve it.

For example, here in Australia our conservative party is presently trying to discard our pathetic carbon emissions targets saying they're unachievable.

In Europe, 40% of emissions come from private cars. If we remove all other emissions, we still can't reach the factor of 4 just because of cars. Are you sure your source isn't BP?

Consumer use of private vehicles and air conditioning / heating absolutely have a non-negligible impact.