Exactly the Govt couldn't visit every work place and set out the exact measures because some places will have 3 people in a 300m2 shed.
It's up to the employer to decide they could temperature check everyone staggered the shifts all the stuff supermarkets can't for members of the public.
They will comply if 2m distancing is maintained at all times and masks are worn in all common areas, canteens, corridors, entrances, changing rooms etc etc.
If you feel unsafe at work then you can 100% speak to the union regardless if you feel it's breaking legislation or not.