Youtube offers a service to advertisers. The users are both the content providers as well as the content consumers, which cancels out. Youtube sells something which is essentially parasitical on the uploaders, who actually create the value that they get to sell to advertisers, but you can say symbiotic instead of parasitic as long as the uploading and downloading are free.
The mail example is great. The post office has no right to withhold your other mail between someone else and yourself, because you threw away the ad flyer someone paid them to deliver.
Meanwhile, I pay for premium and still have to suffer ads, because every video has ads in-band in the content, and I have to watch youtube on someone else's device probably 30% of the time, and have my content (what I would consume not produce) censored and inhibited by bs ai "community standards" and dmca takedowns I didn't approve of, and even without ever looking at an ad, they are collecting and selling profiling data of me which I also don't approve of. So where's my option to strong-arm youtube to force them to fully meet my "terms" and get what I'm paying for? How come it's not reasonable for me to somehow make it that if they don't please ME, that their own server side somehow breeaks unless they conform to what decide is a reasonable fair transaction?
None of this "terms" argument holds up. All they have is might, not right.