Shutting off multiple breakers for one room

We have owned for about 8 months and I was recently replacing an outlet with loose connections in our bedroom. The project ending up taking a long time because I could not get the lights to turn off/outlet to be energized without shutting off multiple breakers.

Pretty much every room in the house is like this, although most of our major appliances are in a single breaker.

I’m pretty sure this isn’t normal, but just how big of a deal is it? Is it unsafe? Home was built in 1981, and previous owner had a 20A circuit installed in the garage about 18 months before we moved in,and an electrician changed an outlet in the utility room to a GFCI outlet right before we closed.