Smart pointers somewhat existed. Without move they were vastly less powerful. (You could have a generic shared pointer without move, but unique pointer has useful properties that you cannot get without move) Non-generic smart pointers - RAII - was very common but that was implemented separately for everything. Having to figure out how to deal with copy was a problem (though many times you disabled it and then passed a reference or a raw pointer to the object - a poor mans move which sometimes was good enough but often was annoying).

More importantly, before C++11 every library I worked with had their own incompatible way of managing memory. None of them used smart pointers in the API, it was always raw pointers (or references where possible but often not possible) and their own documented ownership rules. Any single library was simple enough to follow the rules (hint we got it wrong often), but the combination was very complex and sometimes impossible to combine the two different rules.

C++11 changed how most people manage memory. You could get the same effect without, but it was both more complex, and nobody agreed on the same rules.