Of course there are lots of unknowns, but epidemiologusts can make some educated guesses on how it will see spread. I bet they do take lots of factors into account. Nobody has a crystal ball and real experts will admit where there is uncertainty, but the politicians who get to make the decisions should listen to those who know what they are talking about. There's a difference between wild guesses and predictions based on experience.

The aim seems to be to slow down the spread so health services have a chance of coping.

Of course everyone on the Internet gets to have a say. I've already had someone suggesting I'm an idiot for having an opinion, but I don't claim to have the answers.

Stay well.