Does Power Theme use jQuery?

No, jQuery was removed in the v26 update

Power Pro is coded using vanilla JS (plain Javascript) and doesn't use the jQuery library.

Prior to v26, the theme relied on jQuery, and with many websites containing custom modules that still required jQuery support, a setting was added to retain access to jQuery for existing users while providing the option to disable it for new users.

If you are a new user, you can disable jQuery in the theme settings under Performance, then Super Admin, then jQuery:

theme-settings-disable-jquery-v26

New users can also disable the legacy asset structure:

theme-settings-theme-code-assets-disable-legacy-structure