I’m in precautionary quarantine in Taipei right now, after arriving from a Level 3 country some days ago. As a tourist, I had to provide a phone number of a contact person in Taiwan upon my arrival. They call the number and confirm it works before you even leave the CDC checkpoint at the airport. You also self report your health condition. I then stood in line for 4 hours to get a special taxi to my place of quaranti…
I'm curious as a tourist what happens if you don't have a local contact? What happens if one has nothing but a hotel booking for accommodation instead of a home? I'm guessing that wasn't your case but were there others you heard or saw who were just regular tourists?
Other passengers provided the number of their hotel. The CDC called the hotel and (I believe) checked whether they were aware that these passengers were about to self-quarantine there.
Edit: even if you arrived without having anything booked at all, you can pay to stay at a designated quarantine hotel, though that is more expensive.
Also note that Taiwan doesn’t grant the “visa exemption” usually granted to tourists, when they now arrive from countries assessed as level 3 (requiring home quarantine). I was able to enter during a short window of time where home quarantine was instated but the new visa rules were not yet in effect. So I think it isn’t usual for the situation you described to occur.