Google Assistant now shows ads in some answers

Google seemed to test this approach in February, when at least one user saw sponsored results in his Assistant answers. When asked about it, Google gave a non-answer: “We’re always testing new ways to improve the experience on phones, but we don’t have anything specific to announce right now.”
More ads doesn’t necessarily seem like an improvement to the experience, but that’s subjective. You can let Google know how you feel about it by tapping your profile picture in the Assistant app then Send feedback.