Well, that depends what you mean by sex, doesn't it? And also what you mean by spectrum.
Sex exists so we can make babies, and the word exists to describe the system by which that happens and how it works. In humans, to make a baby, you need one person who can make sperm, and one person who has eggs. People who at any point in their lives will be in category 1 are male, and people who at any point in their lives will be in category 2 are female. Sometimes people's reproductive systems don't work well and they can't make babies, but that doesn't mean they change category.
And a few people, probably about 15,000 in the UK, have developmental differences meaning they're less easy to instantly categorise, but the vast majority have a known developmental or medical condition that's established as existing in one sex or the other, or as having the karyotype of one sex with the phenotype of the other.
To me, that doesn't look like a spectrum. That looks like differentiation into no more and no less than two different and discrete types of person with regards to reproductive role, one of each being both required and sufficient for baby-making, and also a few individuals with rare and specific developmental variants on those two types, each kind of variant development being the result of a particular type of departure from typical development, and having a seriously detrimental effect on the ability of the sex system to function.
If any individual with one of these conditions affecting sex development were to participate in making a baby (genetically), they would still have to do so by taking either the male or the female reproductive role through providing either the sperm or the egg. They couldn't provide a mid-spectrum gamete. These differences in sex development actually demonstrate how binary sex is.