The highlighted items could come at considerable expense that the average person just doesn't have,
Typical defeatist attitude.
First off, the items you
didn't highlight cannot be ignored. Top of the list is the motor vehicle, both for its emissions and expense.
4 years ago I decided it was time to replace my 20 year old gas car (I had just paid a $1000 repair bill, and was dreading the next one). I realized that I could buy a used Nissan Leaf (a car I always wanted but couldn't afford new) for about the same price as a gas car of similar quality. Since then we have had a global pandemic and a big increase in gas prices. My Leaf is saving me money in fuel and maintenance costs, as well as being more convenient and nicer to drive.
I am not the 'average' person - I earn much
less than the average wage. If I could go electric on my meager income many others could do too, but very few do. Most people never count up the costs of owning a car, so they don't understand that in the long run an electric car is generally cheaper. It makes good economic sense even if global warming wasn't an issue, especially since a motor vehicle is the second most expensive thing most people own.
Most people in the Western world overeat, and obesity is a huge problem even amongst the 'poor'. Cutting back on meat (as well as high energy processed foods) will save money not only directly but also in reduced medical bills and general well-being. Reducing global warming is just a bonus.
Now on to the highlighted items:-
1. Improving the thermal performance of your home and workspace
This doesn't have to cost a lot, and just like the electric car it
saves money in the long run. So why wouldn't you do it?
2. Replacing older, less efficient, appliances and lights with modern, more efficient ones
Older appliances need to be replaced anyway sooner or later. Sensible people plan for it and take the opportunity to buy more efficient products.
There was a time when LED light bulbs were a lot more expensive, making it hard to justify replacing incandescents despite the reduced power consumption and lower maintenance. But that's no longer true. Today they are cheap enough that the price isn't an issue.
I began replacing light bulbs and other appliances with more efficient models many years ago, not to save the environment but simply to
save money. Upgrading might a cost bit more to start with, but costs less in the long run. You don't have to be rich to follow that principle. I'm stingier than most and have been living on a shoestring budget for years - but I don't shy from investing in things that will reduce costs in the future. Turns out that often aligns with things that reduce global warming too! Which when you think about it make perfect sense.
Out of 6 items you managed to highlight 2 that you say '
could come at considerable expense that the average person just doesn't have'. But in many cases that's not true. The average person has plenty of money to spend, they just don't spend it wisely.
Exactly what are you trying to prove here? That nobody can afford it so there's no point trying? But that is demonstrably not true, and even you aren't confident enough to apply it to more than 2 of the 6 items. It almost feels like you just want an excuse to not do anything.