Conventional "automated" testing still makes you do all the work: The amount of testing you get out of it is directly proportional to the amount of test code you write.
In contrast, property-based testing lets you specify more general properties about the system under test. This then lets the testing software explore the boundaries of your code, finding new and interesting bugs that you never thought of.
Hypothesis is an advanced property-based system (currently for Python though looking to branch out). This is a talk by the primary author of Hypothesis about the how, why and when of using it, and about how it can help you catch bugs in your software faster and with less work.