Except that time and time again, it turns out that the "leftist dreamworld" is actually cheaper.
Providing subsidized housing for poor people costs less in the long run than dealing with homelessness.
Providing nationalized or strictly regulated healthcare costs less than fully privatized systems where healthcare operators do as they please.
Facilitating active transport such as bike lanes costs cities less, and moves more people more quickly, than focusing exclusively on cars.
What these people actually want is not to save money, but to carefully ensure that any money spent suits only their preferences and identity groups rather than benefiting society as a whole.