Creation of a derivative work without author's consent solely for the purpose of monetisation - sounds legally dubious to me as you couldn't claim fair use.
You think Google didn't already think of that? From Youtube's ToS:
Right to Monetize
You grant to YouTube the right to monetize your Content on the Service (and such monetization may include displaying ads on or within Content or charging users a fee for access). This Agreement does not entitle you to any payments. Starting November 18, 2020, any payments you may be entitled to receive from YouTube under any other agreement between you and YouTube (including for example payments under the YouTube Partner Program, Channel memberships or Super Chat) will be treated as royalties. If required by law, Google will withhold taxes from such payments.
From the average viewer's perspective, it hasn't changed from before, unless you're using an adblocker. And as youtube wasn't sued before, I doubt they will be now.