> all religions have the same benefits
That is true in theory but not in practice. To be recognized you need to be organized as a Körperschaft öffentlichen Rechts which isn't exactly trivial. In practice the Catholic church and the "Evangelical church of Germany" (a confederation of various mostly independent parishes, mostly Lutheran) are the two big ones and everything else barely passes as a rounding error (e.g. there seems to be only one Muslim organization and while they reflect a sect mostly originating in Turkey, they're hardly the largest Muslim sect in Germany).
Also for example the two primary public broadcasting channels ARD and ZDF have a Catholic and Lutheran bias (although this mostly manifests in a handful of very short theological opinion pieces paid for by the respective churches and clergy of the two religious orientations being invited every time ethical concerns are discussed).
Saying "all religions have the same benefit" is a lot like saying all people are equally forbidden from sleeping under bridges regardless of their income. It's not exactly an equal playing field and a lot of the influence of the churches comes down to not just the number of registered members but also feudal property rights and pre-existing contracts (e.g. the Catholic church is one of the few entities that legitimately "owns" land in Germany whereas normally legal subjects are only granted "ownership" conditionally).
And let's not get into public sector institutions like hospitals and schools being operated by one of the two churches and personnel being subject to church labor laws while the majority of the operating costs (in some cases even 100%) are footed by the state.
We only call it pluralism because Martin Luther was successful. Much like our so-called federalism (because Germany was still a lose collection of functionally mostly independent states until around the time of the American Civil War) it's really more of an accident of history that we later rebranded as something desirable.