As clichéd as it sounds, many small actions by many people do add up to a big effect.
I agree with you and believe that anyone who wants to can internally decide, for example, to change three things that come easy to them, two things that are a bit uncomfortable, and one thing that is, subjectively speaking, maybe somewhat unpleasant. That is already, in my example, a total of five points, which I find quite a lot and that might actually make a difference. The next generation might be ready to achieve perhaps 4-3-2 instead of 3-2-1. The many vegans and vegetarians in the younger generation already make a difference. Due to lack of knowledge, the majority of the population started too late, but fundamental developments and realignments basically require a bit more time, and in that regard, I do not want to reproach anyone.
And the construction of single-family homes will be stopped as soon as no new building plots for single-family homes are designated. Surely, people can get used to that, and not everyone will miss it. The desire for a single-family home is not inherent in everyone; often wishes are "simply" created by marketing experts. Still, I am glad to be able to build for now. However, I do not know whether we will still be allowed to operate the well that we will have dug at a relatively high cost for (long).