The verdict
If your decks leave the company as files, or your business already runs on Microsoft 365, pick PowerPoint. Set up a master deck with locked brand elements and a short list of approved slides.
If your team produces many similar decks, nobody enforces the brand and design effort is the real cost, pick Beautiful.ai.
Check how your existing decks import before you commit. Bring real decks to the trial, not a demo. For most small B2B teams I'd pick PowerPoint, because the file format is the standard and the web version is free with a Microsoft account. Beautiful.ai is worth the switch when consistency across a team is the pain.