The death rates will go up, though, if we continue like this, they always lag behind rising case numbers.
We have to stop the normal human interactions for a while, as much as we can anyway. (And that's what NPHET have been begging us to do, for weeks now actually - to minimise our social interactions.)
That's how we can best help the economy.
If everyone was very careful - and, yes, of course it's horribly hard - then community rates would fall again. And we could relax a bit, but, crucially, not too much.
You claim that isolating ourselves is unnatural and indeed it is, but seem to have little compunction about leaving older members of society in this state indefinitely. And yes, to answer your question, I do consider a short term lockdown for everyone better, and fairer, than isolating the elderly and vulnerable endlessly.
The key, I think, is for everyone to hold themselves accountable. The government can't act alone. It's society as a whole must work together to fight Covid 19. Personal responsibility is crucial.