Should you? Obviously subjective opinion. Do you? Yes, a translation is derivative work under copyright and requires permission from the copyright owner.
And leaving aside any ethical debates, the rightsholders may object to their content being presented this poorly just so the distributor can save a buck:
https://bsky.app/profile/littlekuriboh.bsky.social/post/3m6p...
https://bsky.app/profile/brainchild129.bsky.social/post/3m6r...
The humans who do anime/manga translation and dub voices were already paid a pittance for their work, so trying to replace them with AI is really scraping the enshittification barrel.
Language translation is editorial work, and you may make editorial decisions the rights owner disagrees with, misrepresenting their product without permission.