Practically speaking this approach is what we are relying on in the US, too.
Telling people to stay home if they have any symptoms only works if people are actually able to stay home from their jobs.
The demographic patterns emerging from this pandemic are already showing a strong skew along lines of existing privilege or lack thereof. In the US, this revolves around the nexus of race, poverty, and lack of regular prior healthcare access which, to your point, also aligns with the kinds of workers who have fewer rights.
Sweden's approach is controversial because irresponsible individuals put responsible others at risk.
Every car has to pass a bunch of certifications to be legal to drive on the road. It has to pass a (4-, 2- or 1-)yearly checkup, has to be registered, insurance has to be paid, road tax, etc. Also the driver has to pass a theoretical and a practical exam, has to be of certain age, not be under influence of any of many substances, has to obey a bunch of traffic laws, etc. And we also have check for all that, from police controls, to speed cameras, alco-testers, etc.
https://www.independent.co.uk/news/world/europe/oslo-traffic...
As for "suddenly become unacceptably high risk" - it seems that governments do not have much clue and nearly enough info on this particular subject ( COVID )