I'm having trouble finding numbers, but the comment by Vinay was basically saying that each screening is testing for something that has 1-4% chance of killing you. Not that 4% of all cause mortality is cancer, which is incorrect. In the context of individual screenings per cancer, the numbers roughly make sense based on what I could find, but I am by no means an expert.
The specific video/content they are rehashing is the one by Vinay here - https://www.youtube.com/watch?v=-9hQO7X1bmU
I'd highly recommend listening to the Econtalk conversation as there is a lot of nuance behind why screenings (at least as they are done today) could potentially be a net negative at the individual level and don't seem to have improved all-cause mortality in a significant way (according to Vinay).