Luckygirl Firstly, commiserations for your loss. It must make everything especially difficult.
Secondly, I agree with you so much. It doesn't help that we don't know exact statistics, but it seems reasonable to assume that, without some form of intervention, the natural transmission rate would be about 2.5 to 3. That means that the whole country would be infected within a few weeks.
Again, lack of testing means we don't know the exact death rate, but it seems to be about 1%. That means that 660,000 would be killed by Covid-19 - somewhat more than the number of people who die every year from all causes.
Most of those extra deaths would be amongst over 70 year olds, especially males, from a BAME background and with underlying health conditions. We don't know the exact risk, but it's somewhere between 10-20% for over 70 year olds, higher for those in additional high risk groups.
There is currently no cure and no vaccine, so the only thing anybody can do is try to ensure you don't catch it. Even if you catch it once and survive, there are suggestions you don't develop immunity, so could catch it again.
We owe it to OURSELVES and those who care about us to protect ourselves. Without isolation and social distancing, there is no doubt that Covid-19 would wipe out a significant percentage of elderly and vulnerable people. Just think how much the Treasury would save in pensions and disability benefits! I think it's highly unfair to claim others are only concerned about themselves. It's not perfect, but those people being shielded are being given some extra support.