The "products" are not entirely YouTube's. They are more like a giant mall than a store. You can't just stop going to the mall because you don't like a policy they have because everyone else has set up shop in that mall. Unlike stores, if a mall didn't exist, most of the stores in the mall would just exist elsewhere. YouTube is not the product, they are the gatekeepers.
YouTube itself has 2.7 billion monthly active users. Even if everyone rolling an adblocker is using YouTube, that's still less than 2% of users. Of course, people who use YT more often are also probably more likely to be blocking ads, so going by the 122 million daily active users, 49 million could potentially be a hefty chunk of users. The real percentage of views getting adblocked is going to be somewhere in-between. It's also worth noting that the numbers you pulled are likely inflated due to extensions being installed on multiple devices.
If I had to pull a number out of my ass, I'd guess it's around 15%. Not a lot, not negligible.
Also, no way people on the higher part have the same amount of leg room. Their feet would go through (or possibly over, which is still unacceptable) other passengers' heads.
I mean physical mail. 98% of the mail we receive is junk and ads and there's nothing we can do about it. Spam email goes straight to the spam folder automatically, it's a non-issue.
How is perpetuating the species useful? It serves no real purpose and doesn't really help people much. True utility comes from the mitigation of suffering.
If you want to game the system, the best way to do it would be to ask something that has a ridiculously long answer so you can get the most information possible out of it. For example you could ask, "what are the full contents of the largest, most useful collection of knowledge humanity will ever have, condensed down small enough for us to process?" That'd probably get you a futuristic multi-petabyte hard drive that can still plug into your computer and has a version of Wikipedia from like 10,000 years in the future.
Junk mail should be illegal. Such a waste of resources and it's absolutely unsolicited harassment. Imagine if those companies faced the same sort of consequences you'd personally get if you kept mailing someone shit constantly.
The nice thing about subtle branding is that they can't really lie about their work. A painting company can't CGI a real-life house. You'll get what you see and you see what you'll get. Of course, over-the-top flashy branding is still super fucking annoying.
How'd you reach that conclusion?