Why do bike tires suffer from frequent punctures whereas car tires don't?
The main reason is that bicycle tyres are much, much thinner than car tyres. A little tetrahedron of broken glass or a drawing pin that would puncture both tyre and tube on a bicycle won't trouble a car's tyre in the slightest.
A secondary reason is that bicycle tyres with tubes have additional ways to suffer punctures: an under-inflated tyre is susceptible to pinch flats.
It's pretty much as simple as that.