A previous version of Zoom installed a web server on MacOS without telling you, and left it there after the uninstall process. So the answer is no, you can't be sure.

Oh, and there was a known vulnerability in the web server that allowed remote access to your camera. The company claimed this was all intentional and was a feature and refused to remediate it for months. Eventually Apple issues a system update that removed the web server.

https://www.buzzfeednews.com/article/nicolenguyen/zoom-webca...