In what sense is the bible is "clear"/perspicuous?

What do protestants mean when they say that the bible is "clear"? I would assume that it would mean that people reading the Bible or any part of it generally come up with more or less the same idea of what it says, but that doesn't seem likely to be what protestants mean, because the different protestant cults regularly and consistently dream up radically different interpretations of the Bible as a whole and even different members of the same denomination rarely agree on the meaning of various passages. I've heard people say that the bible is clear enough that anyone can read it and immediately understand the "Core doctrines", but this is demonstrably false: Protestants don't agree on core doctrines because they don't even agree on what the core doctrines *are* in the first place. Some people read it and conclude that baptismal regeneration and infant baptism is the go, some people read it and come up with transubstantiation, some people read it and come away denying the trinity, some people read it and think that all you need to do is believe in Jesus to be saved, while other people read it and reckon that you need to do works as well. Protestants say that the Core Doctrines are "salvation issues", but they can't even come to an agreement of what those salvation issues are. I've heard people respond to this by saying something along the lines of "Scripture is clear, but we are sinful humans and our sin gets in the way of us understanding it", but to me that seems to just come across as a flat contradiction: If scripture is clear, then it should be so clear that our sin **doesn't** get in the way of us understanding it. However if sin still has the power to cloud our understanding of the bible, then the bible is **not clear enough** to cut through our sin, and is therefore for all intents and purposes **not clear at all**. Taking all this into consideration, what does it mean for Scripture to be "Clear" and "Sufficient"?