Defining the financial framework, recommendations on house sale / land selection / new construction

that a large part of the baby boomer generation without their own children must be supported by the public in old age raises the question of distributional justice.

......as if the younger generations would increasingly take care of their parents. On the contrary, I read in the forum and see almost exclusively single-family houses without parental care in the environment. The mere presence of possibly more children says absolutely nothing on this topic.

Well, that can't be completely dismissed. Of course, I don’t personally care for my parents (when would I have time, I already have enough on my plate), but I generate a portion of the money currently spent on caring for my parents, and my children will do the same someday. That’s how the pay-as-you-go system works.
Pension is not a big savings pot into which you pay for 47 years and then withdraw "your share"...

So yes, childlessness is a problem... especially because childless people have usually worked full-time their whole lives and therefore generally have a high pension entitlement. But the most important component, children who in turn keep the economy running, is missing. One can debate that for a long time.

But, and that’s where we got to. I can understand that one eventually loses the desire to work, possibly also because a lot of tax money doesn’t go where one would like to see it. But the conclusion to retire earlier is the wrong one for the reasons discussed above. Those who retire earlier but could still easily work become an unnecessary burden on the social security system themselves... the argument thus bites its own tail. People complain about egoists who live off taxpayers and in doing so become egoists themselves. That can’t be it.

Of course I don’t take care of my parents myself (when would I, I already have enough to do)

It is not an obligation, but I don’t understand why it should be “natural” not to take care of one’s parents. I certainly don’t mean full-time care, but I find it a nice and desirable solution if the parents live in the house or at least close enough. I myself might not have this situation, but my parents lived in my house and I also had a job + side job + construction.

(when would I, I already have enough to do)

I don’t just claim it, we did it, so it works, we are not superhuman after all. Of course, both sides have to want and be able to do it, but I perceive rather a “alienation” between young and old in this regard in my environment, which I actually find unfortunate, because ultimately both sides can benefit. I really know a few peers with real estate who feel like pure money providers/inheritors but otherwise excluded. Otherwise, I certainly agree with you in some areas. Being free from work does not automatically mean happiness, even if you wish it very much for yourself. I wouldn’t have to work anymore and still like to look for something.

No, it's not that simple. There are situations where it doesn't work either time-wise or personally. Just because it works for you doesn't mean it has to work for me...

For example, I do a job for which hardly any new talent can be found anymore. I could also say, "Why? It's fine, I've been doing it for 15 years..." But it's just not that simple.

Just because it works for you doesn't mean it has to be the same for me...

I never said that either or where do you read that?
I just don't see it as "natural" (quote) not to take care of one's parents or to have them living in or near one's own place of residence, and that there are plenty of examples in my environment alone that this can work. And yet everyone decides that for themselves......how you do it is none of my business and I don't care either.

For example, I do a job for which hardly any newcomers can be found anymore. I could also say "Why? It fits, I've been doing this for 15 years..." But it's not that simple.

A comparison of apples and sausages; pears would be too similar to apples. A job and my mother/my father can in individual cases lead to a different assessment......can.