This was in a large apartment tower complex in the semi-countryside. Not sure if it's always like that, it's the only apartment I stayed in. In Seoul I've only lived in villas.
Perhaps it's a countryside thing because I've also noticed noisy public speakerphones in the streets blasting PAs about random stuff, but I haven't seen it in Seoul.
Overall though, the local governments do spam your phone with alerts about all sorts of remotely relevant (IMO) things on a daily/hourly basis. I find it annoying but it's just how it is here. Today they were spamming about possible debris from a NASA satellite deorbiting.
Here is a very collectively oriented society. That's my take on it. High trust communities, so much so that things like this are possible: https://mobile.twitter.com/AntoineGrondin/status/16123864859...
It’s very nice of you to respect cultural aspects, but I suspect that at least some koreans also simply disconnect it and accept the risks :)
I'm one of those foreigners who didn't appreciate that my apartment's management office would blast public broadcast messages directly inside my apartment at 8AM to say stuff like "there's a farmer's market in the parking lot today (like every week)". I asked them to stop spamming my household via their PA system for non-emergency stuff and they thought I was a antisocial psychopath.
Then I learned and just disconnect the PA system. They don't mean to invade my privacy, but my privacy boundaries aren't the same as theirs.