And not only one single advertisement, but two advertisements after every 20 minutes or so. 

This is not a good experience. I don't know why they charge so heavily for internet if they are ultimately going to show us advertisements within OTT platforms.

There are these people who charge us for every single thing we do and here are us all, common people who struggle to make even single dollar.

This is just corporate robbery and nothing else. In the name of providing services, actually these companies just sell us advertisements even though we are already paying heavy amounts for internet.

When we are buying premium membership for Amazon Prime or Netflix or JioHotstar, then why do we need to watch advertisements?

I can't understand this.

This is a pure case of exploitation from these big corporate houses. If we wanted advertisements, then we would have used cable operators only, we wouldn't have shifted on these OTTs in the first place.

And no one talks about this, because everyone of us have become adjusted to this and we just feel this is the normal.

No this is not normal, if you have paid for something, you don't have to watch ads while using that product or service.

Same with phones that have bloatwares or with software that sell advertisements even though they are paid services.