Comment by andix
In my experience concrete walls and ceilings in apartment complexes completely block 5 GHz signals. Even through modern triple glass windows most of signal is lost. I can't receive any other 5 GHz networks inside my apartment, but around 50 on 2.4 GHz, which makes 2.4 nearly unusable anyway.
This is even more true for the WiFi 7 frequencies at 6GHz
The old tales about interfering with your neighbors, prisoners dilemmas, and claiming moral high ground from setting it to low is old school WiFi mythology that continues to be parroted around