edda-for-dummies:

Yes, or at least I very much consider them gods. They’re a “different people” from Asgard’s gods and thus live on a further stretch of land, and also different from the rarely mentioned Vanaheim. Many of them still marry the other gods, have been their parents, or share equal powers over human life and the environment with other gods.

Jötuns are also the foes of the other gods. Many old myths tell stories of culture fighting against natural troubles, because that’s a very important problem for many human societies. I think that’s exactly why the giants (jötun, hrimþurs) can seem like they’re “worse” or “monsters” in some stories.
It’s not that they’re not gods or goddesses, it’s just that they’re beyond the control of humans and other gods.

A goddess of good crops and farm soil, like Sif, feels like a somewhat “regular person” if you think about a viking age home and life. That’s a familiar thing and a thing people can affect with their own work – whether tending to the land or offering to the gods, usually both.
Compare Sif with Rán, the personification of ocean waves that drown people, who’s a giantess and the wife of sea god/giant Ægir. You can offer to her, sure, and you might want to do that too and only sail on a day the sea and sky look clear. But really there’s nothing you personally could do to control the sea and the ocean.

Asa-goddess Sif can get angry too, and you’d be famished for the winter if you didn’t get a good crop from your field when autumn comes. But Rán would murder you on the spot if she felt like it, and steal all your belongings to the deep with her too.