"A few hubs"? Just Hurricane Electric has presence in many, many IXPs, and they're not even the largest transit provider:
* https://bgp.he.net/AS6939#_ix
AT&T, the largest transit provider, has a ridiculous number of peers:
* https://bgp.he.net/AS7018#_peers
And there are several different major global providers:
* https://en.wikipedia.org/wiki/Tier_1_network
A lot of the Big Tech companies are also building their own private fibre networks so they don't even have to worry about sharing infrastructure with the telcos: