Unless you're using a camera that supports optical auto-framing (90%+ don't), Zoom is merely stretching/cropping your camera's image to re-frame participants, which will typically look rough.
Your camera is not actually zooming in on the participants, which means you're just taking the pixels you already have from the wide-shot and making them bigger - this will rarely ever look good (unfortunately, this has become the norm in 2024).
I'd ask for a screenshot without auto-framing enabled, and then with, just to confirm whether this is the actual issue.