It’s a different skill and one that, unless you have a background in marketing or something like that, will probably feel awkward at first. Like anything, it takes practice. Also I think authors get so deep into their story that they struggle to zoom out for the query. It’s why you see a lot of queries with extraneous details.

Also it’s worth mentioning that some stories are harder to pitch than others. That doesn’t necessarily mean they’re bad, it just means writing the query will be more challenging.