Sort of-but I haven't found a turnkey "OBS, except it automatically handles display changes and repairs broken capture." The closest concrete option is Advanced Scene Switcher, an OBS plugin that adds rules for display/source conditions, video failure detection, scene switching, and notifications. It supports Windows, macOS, and Linux.
That's still "configure the automation once," rather than a genuinely maintenance-free replacement.
Not really as a turnkey app. vMix, Ecamm, Streamlabs and the rest all have the same "display capture breaks when the monitor setup changes" problem, because the OS hands out a new display ID and the capture source is still pointed at the old one. The practical fix is to keep OBS and add automation on top. There are two ways to do that.
While there isn't a magic out-of-the-box software alternative that solves this natively, you don't actually need to ditch OBS. You just need to install the Advanced Scene Switcher plugin.
The requirement I would add is: never silently replace a failed capture with a different screen. Reconnecting a monitor should not accidentally put a private window on the stream. My preferred recovery sequence would be a safe holding scene, a source reset, a check that the intended source is back, then an alert if it still fails. Also, an unchanged picture alone is a poor failure detector: sometimes the slide really is that boring.