My coworkers had kids, and a longer commute, and still took public transit to get to work.
> The idea of carting kids to soccer practice on the bus,
10 minute walk, not that I was interested in soccer as a kid (or as an adult).
> or shopping for a family of 4 and taking the bus with 100 pounds of groceries is absurd.
We have this fantastic new invention in Europe, called "deliveries". It's like Amazon, but it's your own supermarket.
Also, see previous point about building supplies. 25 kg may be ~55 lb not 100, but I have hauled both a 25 kg bag of cement and on a separate occasion a 25 kg bag of decorative rocks, in my rucksack, on a bus. I have *literally* seen someone take an actual kitchen sink with cabinet on the tram around here, something like this: https://www.amazon.de/Küchenschrank-Küchenspüle-Unterschrank...
Even on the one time I wanted more than I could carry (four 25kg bags of cement at once, and it seems these stores don't deliver specifically cement despite delivering everything else I've ever wanted), is was a case of "ask a friendly neighbour" not "buy your own car just for this"; but even if the neighbours had not been available, the building supplier does have rental vans specifically for people buying lots of stuff, so still no need to buy a car for this very occasional scenario that the thing you want is something they sell but don't deliver and it's too big or heavy to take on the bus.
Also, lunch breaks are generally long enough, and stores numerous enough and convenient enough, to do whatever top-up shopping is needed every day (except Sunday) rather than putting the whole thing into a single massive shop — and even if I forget shopping during lunch, my previous commute took me past at least 7 supermarkets and other decent-sized stores, plus two entire shopping malls at exactly where I changed lines — and additional options on two more shopping malls if I took a marginally longer route than my default.
Other things you may find ridiculous "what about a hospital visit!": it is between "very cheap" and "free" to call an ambulance here, and not "unaffordable even if you need it" like I keep hearing it is in the USA; and also the nearest hospital is a 16 minute public transport route, of which 14 is "bus" and there's a total of 100m walking (in total between both ends) going between the bus stops and the building doors.
Strollers/push chairs/wheelchairs: there's dedicated space on the bus, and more than enough space on the trains even on the ones without designated zones for them (and many do have dedicated zones for them and bikes).
(One thing I don't know and don't claim to know is how good in practice wheelchair access is in Berlin stations: I do know that the London network wasn't as good as it needed to be when I left the UK, but that's all).