It's interesting (although it may raise more questions than answers) to note that several of the prominent Greek goddesses -- the two you mention, Athena and Artemis, as well as Hestia, perhaps more famous as the Roman Vesta, are noteworthy in particular for their virginity, and therefore in some sense of their rejection of the feminine role as mother. Hera/Juno, who held the most "royal" position as the wife of Zeus/Jupiter, was certainly widely worshipped, but her position in so many of the myths that identified the Greek gods was as the jilted wife who sought catty revenge, perhaps culminating in her role as the antagonist in Vergil's Aeneid. In the Iliad, arguably Hera's chief power is her ability to seduce her husband to distract him, which may say plenty about women's roles. Finally, particularly telling is the supreme dominance in power of Zeus over all the other gods, male and female; none of them, however powerful they were individually, could come close to challenging him, at least in Homer's Iliad, where he explicitly offers the challenge:

'Go on: attempt it, and see. If you tied a chain of gold to the sky, and all of you, gods and goddesses, took hold, you could not drag Zeus the High Counsellor to earth with all your efforts. But if I determined to pull with a will, I could haul up land and sea then loop the chain round a peak of Olympus, and leave them dangling in space. By that much am I greater than gods and men.’

They all fell silent as he spoke, astonished by the force of his words. But at last a goddess, bright-eyed Athene, answered: ‘Our Father, son of Cronos, Lord over all, we all know your irresistible power, yet none the less we pity the Greek spearmen, doomed to die and fulfil their sad fate. We will hold back from battle, as you order; but we will still offer them our good advice, so they may not all suffer your wrath.’

There are theories that continue to be pop up here and there about the matriarchal dominance of religion and possibly even society in Bronze Age Greece and the Hellenic pantheon as a patriarchal Aryan transplant onto this, which is supposed to explain the mythology of the Titanomachy -- the overthrow of the "parents" of the Greek gods and their replacement by the new pantheon. This was particularly popular back around the 50's and 60's, and is easily seen in the fiction, for example, of Mary Renault, which is how I chiefly encountered it. While an intriguing hypothesis, it doesn't stand up well to the evidence we have of the historical development of religion in the area, especially once we began deciphering Mycenaean religious texts after the decoding of Linear B.

An even more striking case is Japan, which was historically even more sexist than the ancient Greeks although the Shinto pantheon was even ruled by a goddess.

Followup question: is it accurate that the Japanese were more sexist than the Greeks?

Edit: I'm not really expecting a simple numerical rating or comparison. To me the question "was Japan more sexist than Greece" in the context of this sub implies a host of smaller questions like "what were property/marriage/divorce rights for women in greece/japan" and "how were women portrayed in art and entertainment in greece/japan" and "how inclusive of women were cultural/social institutions in greece/japan". No one in this sub should expect a single sentence answer "yes japan is more sexist than greece" and anyone who gives such an answer should be shot.

The reason I asked is because from my understanding the Greeks kept their women under lock and key and didnt even allow them to participate in festivals and holidays, which strikes me as exceptionally sexist, so I was a bit thrown by the OP casually saying that Japan is more sexist as if it were an accepted fact.

Mary Beard mentions this in her talk on The Public Voice of Women. It is in the Q&A, at 75:35.

"The one trap one has to avoid falling into is thinking that female goddesses are the analogue of mortal women..." And she goes into quite a bit of detail, referencing Athena, in particular.