OBS itself is a tool for creating new video files from original sources by capturing and compositing stuff.
I'd say it a little bit differently:
OBS is a live TV studio. Everything it does is live. Live captures, live overlays, live everything else, live streaming, and "live-to-tape" recording. Everything OBS does is effectively live-on-air.
If that's what you want, that's great! One of our attempts at making a pre-recorded church service during Covid, used OBS to put lyrics on the songs while the lyrics operator followed along as if it were live. And then the live-to-tape recording that OBS made of that, we uploaded to YouTube.
If you can't be ready and do all of the edits that need to be made, live in real-time as things play out, then OBS is not the tool for you. You need an editor, which is something different as mentioned above.