You completely missed the point, the emphasis is at the end of the sentence:
in a way that people think to be very intransparent, undemocratic.
Of course they call the shots. But you can do that in various ways. You can engage with people and include people in those decisions in various ways. Wikipedia for example does a technical survey every year, asking: "should we focus our technical work on area A, B or C? What do you guys think should be prioritized?"
That does not mean that some specific task needs to be prioritized just because one person wants that. But I heavily doubt that the devs have an idea how popular or unpopular certain ideas/wishes are with Lemmy's users.