In defense of Berlin's Tiergarten, it was originally a hunting preserve for deer (and Hasenheide was for rabbits), so it's big and intimidating. But there are still facilities in it that serve the neighboring residents. And throughout Berlin there are multiple volksparks, people's parks, which have everything the author mentions.
In most cities, parks evolve to serve the residents.
I love Tiergarten, but I see the surrounding being overrun by these as why it is so underrated/unknown. Otherwise an amazing place to cycle through, chill on the grass with friends or grab a beer in Café am Neuen See.
Last weekend there was a free concert (PopFest) put on for all to enjoy.
It struck me, as I was riding through one of the worlds' most livable cities, that the careful planning for all of these locations was done a hundred or more years ago .. and that the love of the city's planners for the city's population is clearly evident. Whether its the open fountains, fresh water supplies, well maintained and curated lawns and gardens, easy and accessible public transportation, or the incredible asset to city-dwellers sanity that is the Danube Island, its very clear that this is a city which cares about its people.
And I've seen it all over Europe, too.
In the USA, where I lived for 15 years before this - we had the benefit of enduring hourly commutes, twice a day, on elevated platforms above the concrete jungle, and dare you ever left that commute to explore the neighborhoods usually ignored, there is not much public space to be had that wasn't occupied by misery.
Its a stark contrast in care on the part of the governments involved. I'll take Vienna's park-loving social system over that of LA or SF, any day.
But you are correct, there's not enough swimmable lakes in Berlin and when the weather is nice you better drive somewhere in Brandenburg if you don't want to be stuck in a fully packed pond with 1000 others.