the RCN says we all have to look the same all the time,
I think that is the root of the problem.
While I am some time out of uniform, I have worked at any number of industrial sites including underground mines, surface mines, industrial facilities, oil & gas production facilities, construction sites and environmental remediation sites (which have any number of hazards such as hydrocarbons, PCBs, chemicals, heavy metals and radioactivity, often many at the same site).
Each site has a health and safety person (typically qualified in occupational health and safety) that looks at the site and the hazards then prescribes the appropriate PPE&C (personal protective equipment and clothing) for the site. And the PPE&C may change based on conditions, tasks, etc.
So sometimes fire-retardant coveralls are required. Sometimes just coveralls. Sometimes basic construction PPE&C.
Workers may be required to review AND DOCUMENT (a little card carried in the pocket) site hazards before beginning a task to make sure appropriate precautions have been taken.
Specific situations may require specific levels of hi-vis, specific types of boots, specific types of gloves, etc.
Basic PPE&C is: 6" 'green triangle' safety boots, gloves, long pants, long sleeve shirt, high-vis vest, eye protection, hard hat. Commonly add-ons for specific hazards may include hearing protection and / or face shields.
Respiratory protection is a whole other field that may range from a dust mask to full-face respirator to supplied air depending on the hazard.
The point being that a wide variety of items may be required based on hazards. Experts are available to ensure the correct items are specified. Workers are obligated to wear what is specified (zero tolerance for non-compliance on health and safety issues). Workers may refuse to work if the conditions are considered unsafe (e.g. appropriate PPE&C is not provided). Indeed, workers are ENCOURAGED to speak up if they see something that they think might be unsafe.
Sharing my perspective and experience. Trying to make everyone the same in the face of different hazards is inconsistent with health and safety requirements and industry practice.