It's even gamified a little bit; the add-on tracks how much time your submissions have saved other people (so if you block out 30 second sponsor spot, and 10 users skip that spot, you get credited with 300 seconds of time save), and there is a leaderboard. Popular YouTubers like Linus tech tips will have their sponsor spots identified and submitted within a couple of minutes of uploading because the high view count is worth a ton of time save.

Something else a lot of people don't know is that it can be configured to skip things that are not simply sponsor spots, stuff like filler, intro and and cards, begging for subscriptions, and so forth. That add-on is the single greatest quality of life improvement YouTube has ever seen.