Why did god create diseases?

[Chas]

Which leads to a follow up question: why beat around the bush? Why not just install the lower birth rate from the beginning and skip the unspeakable agony and death that diseases have caused all life on earth?

The lower birth rate propensity is built in. It just doesn't kick in until it's needed. Natural population control is a fact of nature.

I would call you a fantasist. Are you happy or unhappy with reality?

That's not how it works. There is no 'built-in propensity' for lower birth rate. The only 'natural population control' is death.

Birth rates are partly a function resources, as is infant mortality.

Populations of animals are often cyclic, boom and bust phenomena.