This is a very US-centric view, where public subsidies for tennis courts exist. In Germany for example, there's no such thing as a public tennis court, as far as I can tell.
Do parks in Germany have basketball courts, football pitches, or baseball diamonds? Is it that parks provide for sports that's US centric, or is it including tennis courts in that set of amenities that's US centric?
There was definitely a public basketball court and a football pitch within a few blocks of where I lived in suburban Münster. So can't speak for all of Germany, but there are some public spaces for the common sports in that country.