I only use OBS to record my desktop or game clips. So, it didn't make any sense to me to tolerate OBS wasting CPU/GPU cycles when I'm not using it. I guess if I used OBS several times a day, it would be a different story.
Anyway, it didn't take long for me to make a script that has a video recording toggle hotkey. It quietly launches OBS and starts recording the desktop... then when I press the hotkey again, it stops the recording.. and quietly exits OBS. I didn't have to sacrifice any functionality or switch to another app.