Both of them lost their major powers at the same time. Sasuke lost his Rinnegan without actually getting to do anything ...

While he was eventually able to regain his strength with the Eternal Mangekyou Sharingan, along with the Rinnegan, possessing the Curse Mark would have potentially amplified Sasuke's power to an ...

To make things worse, Sasuke even lost his Rinnegan, and now, the only power that he truly has is one Mangekyo Sharingan, which was extremely underutilized to begin with.