[falcolas]

It adds more support (10x to 20x) for the content creators than ads, with the bonus of not watching ads.

For some people, this is quite valuable.

As a side note, the video downloading is made available in the mobile app as well.

[alpaca128]

I could also invest those monthly bucks in some Patreon subscriptions to my favorite channels, which gets them drastically more and makes them less dependent on YouTube. It would even let me set the precise amount and distribution. And not pay a shady ad company on top.