Lots of people! If you were closer than 2m for 15 mins, you'd be asked to self isolate. Otherwise yes, people are going in to many, many workplaces, some without PPE like I do (teacher)
So, if 6 out of 24 pupils you were in a room with one day were tested positive, you'd just all carry on? Or send a supply in the next day? No, you'd have PHE in, a deep clean, testing for some of the others, and self-isolation. Depending on the risk assessment would depend what you'd do going forward.
Care homes did indeed have multiple outbreaks in one home, and several care home staff members died. It was shameful. They should have had PPE.
You don't just have to put up with large numbers testing positive in your workplace.
Some people here are confusing general risk- i.e. I might come into contact with someone in my workplace, with actual risk, multiple people in my workplace have corona and so the risk to me going back in is quite high if there are other asymptomatic people about.
The whole point of Track and Trace is to track people who have it, trace those who have it, and tell them to self-isolate! That means most of the workforce in an office in contact with those 6 would need to self-isolate. Either the OP is going to be very lonely going back in, or they are not following this (if they tested positive very recently).
Op talk with your boss, talk to them about the safety measures, who is self-isolating, what public health says and take it from there.