Their main concern is our lifestyle - they want to reduce it.
Absolutely spot on, they want to reduce our lifestyle, yours and mine, not theirs.
CS Lewis got it spot on in “Mere Christianity”.
PRIDE is the biggest sin. We all have it, we all despise it (in others).
Many other minor sins such as greed and envy are really just symptoms of pride. The greedy man wants more for the sake of having more, but that person is rare. Most greed is to have more - THAN ANYONE ELSE.
Now, applying this to the left. They are so PISSED that the average person has all the same luxuries that they have, that they seek to use force to deny those luxuries to others so that they can think themselves better.