> The weird thing is, that after reopening many thing/services in many places, there were very rarely any new spikes in new cases. We've all been expecting a spike after every measure being removed, and it hasn't happened in most countries

I think at least part of the people keep distancing to some degree, and even if that does not prevent a new spike or outbreak completely, it slows it spread.

That's another critical difference to the Spanish Flu: Spread is much much slower. With the flu, most people become ill and infectious within one day. If that were a dangerous flu pandemic, the world would have had less than two weeks to shut down most cities.

Here in Germany there has been a lot of lifting of restrictions for weeks now but still everyone wears masks in shops/transit & a lot of people work from home (that didn't before). No large gatherings (like concerts or conferences) & international travel is a small fraction of what it was pre-corona.

So I can imagine there's a large effect still of even these milder (and partially voluntary) measures.

Have you checked out Florida, Arizona, or California lately?