Nowadays ppl have started writing test class for just coverage and prod deployment rather assertion. Assertion is mentioned in some last corner just as a point with inadequate emphasis. When the code is written itself assertion should be written.
You shouldn't be using the Developer console, rather you should use the IDE like visual studio code since the Salesforce does not provide the support of Developer console.
I didn't see anything about assert methods. In last video also which was about trigger framework, I saw for loop inside for loop and same logic was getting executed two times while inserting and updating (same speaker). I love this channel but i was not expecting this from someone who is a SENIOR Salesforce developer.
