Getting to the IX doesn't mean you're home free, though. Your transit providers are also oversubscribed and links further down the chain could get congested.
>https://arstechnica.com/tech-policy/2014/05/comcast-is-the-o...
>Comcast argued that it could be considered a Tier 1 itself, as less than one percent of its traffic requires transit.
>As Comcast's market power continued to increase and consumers had less choice, they actually started demanding payments for connectivity. A larger Comcast will be able to demand even greater payments.
As for T-Mobile/ATT, they are Tier 1 providers who again get transit for free. Spectrum is the only resource that is scarce in that scenario.
The same rules don't apply to the larger ISPs. This market is not fair.
Bandwidth is finite. Links can become congested.