The same reason every other country out there is ill-prepared – with the possible exception of China.

Nobody knows what they’re doing. The Germans just don’t know what they’re doing particularly well.
Why can’t Germany deal with the new COVID crisis?
Germany is deep into its fourth wave of the COVID-19 pandemic, but yet again its authorities and politicians seem ill-prepared. Has no one learned from the mistakes?
It goes like this, if you haven’t noticed:
Laurel: Get vaccinated to protect others.
Hardy: OK. Got vaccinated.
Laurel: And keep wearing a mask to protect others.
Hardy: But I got vaccinated.
Laurel: The vaccinated are just as contagious as the unvaccinated.
Hardy: Then why did I get vaccinated?
Laurel: To protect others.