Back-of-the-envelope calculation: a slacker suffering from insomnia watching 5 streams of Netflix at once × 20 hours/day × 365 days non-stop would otherwise watch the whole catalog in less than a year.

Convinced?

Not really.

If we unpack your calculation to slightly more typical human behaviour: Watching 1 stream × 10 hours/day × 365 days non-stop, one person would need 10 years to watch the whole catalog.

Doesn't seem unreasonable to me.

You didn't get the core idea of my calculation: to show that Netflix has times of magnitude more than just 36k hours of content.