The verdict
If you need visuals in volume, such as social images, ads and one-pagers, and a free place to start, pick Canva. It covers more work, and the brand kit keeps a team consistent.
If your problem is the blank first slide, and your team already has a PowerPoint or Google Slides template it likes, pick Plus AI. It gives you a first draft from a report or call notes without changing where decks live.
For most small B2B teams I'd pick Canva. It costs nothing to try and does more. Pick Plus AI when decks are your only output and the template is the asset you want to protect.