Off topic question.
> I imagine 90%+ is peered or hosted inside ISPs, not via transit
How hosting inside ISPs function? Does ISP have to MITM? I heard similar claims for Netflix and other streaming media, like ISPs host/cache the data themselves. Do they have to have some agreement with Steam/Netflix?
The CDN/content provider ships servers to the ISP which puts them into their network. The provider is just providing connectivity and not involved on a content-level, so no MITM etc needed.
Yea netflix will ship a server to an ISP (Cox, comcast, starlink, rogers, telus etc) so the customers of that ISP can access that server directly. It improves performance for those users and reduces the load on the ISP’s backbone/transit. Im guessing other large companies will do this as well.
A lot of people are using large distributed DNS servers like 8.8.8.8 or 1.1.1.1 and these cansometimes direct users to incorrect CDN servers, so EDNS was created to help with it. I always use 9.9.9.11 instead of 9.9.9.9 to hopefully help improve performance.