If the experts spoke directly to us over a cuppa, they would say, for instance, "I've looked at the evidence, and it shows that it could rain a lot today. The worst thing that could happen is that we all get drenched and get pneumonia, and our houses are flooded. It may happen, or it may not happen, but it is quite possible that it will, so we had better be prepared for it. My advice is to put on a raincoat if you go out and take an umbrella, and avoid leaving your windows too wide open."
So you see your neighbour over the fence and tell her "It will be a downpour. You must not go out without a sou wester and a golf umbrella or you will end up in intensive care. Oh, and your home will be flooded out."
Note the words the scientist used - could, quite possible, may, may not, advice, best be prepared for the worst Now your words to your neighbour - will be a downpour, must not, will end up in intensive care, will be flooded out. Who is responsible for the neighbour being scared witless, you or the scientist? If the media alter the meaning of what a scientist has said they are doing exactly the same thing
Then look at two scenarios.
1) As above - evidence shows what could be the "worst possible" and the media emphasises the worst and spreads the bad news gleefully, but it doesn't come to the worst. It rains, but not as heavily as the "worst possible" that it could have. The storm drains cope, so there are no flooded streets. Because the bad weather was forecast, there were no windows wide open to the rain, so no carpets or sofas were ruined. People go about their business as usual, but wearing their raincoats and wellies (as advised) and have umbrellas ready for the worst of the rain. No-one gets soaked through so no-one gets pneumonia. Your neighbour is very angry that the scientists predicted such disaster and worried her into a near nervous breakdown about her safety and her ruined soft furnishings.
2) The experts don't mention the possibility of the "worst possible" for fear of worrying people, but the worst is what happens. No-one expects bad weather, so it comes as a surprise when the heavens open and a year's rainfall happens in ten minutes. No-one has a coat, let alone a raincoat and an umbrella. People fall into over-flowing rivers. Windows are open so carpets are soaked. The streets flood, the storm drains can't cope, cars are washed away, the floodwater pours in under doors and fills up the ground floors of houses in low-lying places.
Scientists and experts have to pass on their expertise, which they have spent decades of hard work to gain, citing the evidence and giving reasons for their conclusions. They can only reach those conclusions from the available evidence. Where there IS NO EVIDENCE YET as with Covid at the start of the pandemic, they can only say what could be "worst possible" and "be prepared for the worst"
The media pass it on further, to the public, and they have a duty to put in some work too, at understanding what they are passing on and giving a truthful and realistic picture of it. Unfortunately, the media loves a sensational story, or a conspiracy, so the public often gets a distorted version - which then whizzes round the world faster than the genuine reports, and is very hard to replace with reality.