Here in Taiwan, they actually had infected people stay at hospitals even if they weren’t in critical conditions, in order to isolate them.
People who were ordered to quarantine after returning from overseas or who had been exposed to someone which covid faced huge fines if they went out. A couple of people were caught and were fined up to the equivalent of about US$30,000.
People returning from overseas were required to verify the receipt of a text message before they were allowed to clear customs. They were required to answer calls during quarantine or were fined.
But that’s what you can do when your country had cases in the hundreds and not millions.