When SHTF it is gonna be something like “going to the shop” , yes I agree, almost anything can be usable for something.
In first period most usable stuff gonna be “stripped” and taken (weapons, tools, food, stuff from shops etc) as the time go people will realize that they can use also some other stuff ( fuel from tanks,batteries from cars steel plates and steel pieces from everywhere – for homemade protection and covers, carts for moving stuff etc)

At the end people strip door frames and parquet for fuel.
Yes everything is usable, but since we are preppers here we gonna use common sense and scavenge usable stuff BEFORE non-peppers see it is usable actually.

People use to take cars in first weeks of chaos, abandoned cars or steel cars from people. Later they figured that battery and fuel from that car worth more then car, so use common sense.

And have some good tools!