I believe his dormant powers had to be activated by his father, and when Quill choice to reject his father, he lost his powers.
Comic book lore dump incoming
When the Scarlet Witch was first created by Lee and Kirby, her powers were not well defined. She had "hex powers", that could cause random unlikely events to take place. This gave creative freedom to the writers, as it actually meant that her powers could be used for any purpose required by the plot.
[4] Despite the character's name, she had those powers as a
mutant, and not because of actual witchcraft. Later writers gave her an increased control over her power, so that she could cause specific events and not just random ones. Englehart also made the character explore witchcraft under the tutelage of
Agatha Harkness, a trait that was kept by later writers. The effects of her powers are varied but almost always detrimental to opponents, such as causing the artifact the
Evil Eye to work against the inter-dimensional warlord
Dormammu,
[111] forcing the robot
Ultron to short circuit,
[112] or a gas main underneath the
Brotherhood of Mutants to explode.
[113] Scarlet Witch also has the potential to wield magic and later learned that she was destined to serve the role of Nexus Being, a living focal point for the Earth dimension's mystical energy.
[114]
Writer
Kurt Busiek redefined Scarlet Witch's powers, and maintained that it was in fact an ability to manipulate
chaos magic, activated due to the demon Chthon changing her mutation at birth into an ability to wield and control magical energy. This was offered as an explanation for her various feats that seemed to go beyond probability alteration, as well as why her hexes almost always have an effect that is favorable to her goals.
[66] During Busiek's run as well as the subsequent run by
Geoff Johns, she was shown to be capable of large-scale spells given enough concentration and time to shape the chaos magic to a specific goal, including the resurrection of
Wonder Man.
[66]
Her powers were retconned in
Avengers Disassembled, removing chaos magic and turning them into reality warping. In
House of M, this new power was enough to change the whole universe.
[115] Her powers were retconned back to their previous ones in
The Children's crusade, and the previous events attributed to an outside force that had temporarily increased them.
[84]