It means at least taking the most basic precautions if you're positive (or think you may be). Such as staying away from other people as much as possible, wearing a mask in enclosed spaces, minimising where you go indoors, etc., avoiding places where there may be vulnerable people such as healthcare settings, etc. If you're, say, a worker going into people's houses, at least tell them you may have covid and let them make the decision about what precautions they require or whether they want to rearrange instead.
At the moment, lots of ECV are back to staying home because of the sheer number of reported infections amongst the general population. That's not good for business, it's not good for NHS, etc. Those people will be waiting for infection numbers to come down again before they return to going out and about, spending their money in the economy etc.
The majority of the public may have forgotten covid and be going about as if it didn't happen, but the ECV won't be, that means huge numbers of "missing" customers, missing staff from the workplace, etc., and is the reason for the massive number of infections at the moment. I can guarantee that many vulnerable and most ECV havn't forgotten about covid and don't have a blase attitude of thinking it's just a cold, therefore are back to staying away!
Thanks for clarifying.
The problem with this approach is that it's based on the idea that if people knew or thought they would test, that would lead to people who are afraid of covid now being less afraid and thus using businesses more. Given that Omicron is incredibly contagious, that LFTs even if the state were to fund them again and everyone were to use them regularly don't reliably provide proof as soon as someone is infectious, this is pretty optimistic.
People who are concerned about getting covid know that it's everywhere. The things you mention aren't going to stop that. I'm not sure it's more desirable to have ECV people wrongly thinking those measures would mean they weren't at risk, even if that does mean some businesses folding.