This actually deserves an answer. Google can do this because it has a clout on ISPs to interconnect to them, and ISPs do have an incentive to not break Google,

This actually deserves an answer. Google can do this because it has a clout on ISPs to interconnect to them, and ISPs do have an incentive to not break Google, so Google's job is easier than many others which don't operate an autonomous network. Essentially Google has its own ISP (which to be clear is separate from Google Fiber's), and you don't (unless you're representing a large corporation here). Also the only cost for ISPs to connect to Google is fiber and equipment costs, which incentivises ISPs to peer with Google. The real problem of deploying IPv6 is that despite record-high prices of IPv4 addresses and the cost of CGNAT (both monentary and performance-wise), it's still cheaper to do IPv4 only rather than dealing with the hassles of running both IPv4 and IPv6. With IPv4, you can just pick a Tier-1 carrier and you're guaranteed to traverse the whole internet, at least those who didn't proactively blocked you. With IPv6, you are exposed to ugly Tier-1 fights like when Hurricane-Electric tried to interconnect to Cogent to no avail (https://www.datacenterknowledge.com/archives/2009/10/22/peering-disputes-migrate-to-ipv6 https://www.datacenterknowledge.com/archives/2009/10/22/peer...), even trying to bake a cake à la Microsoft-Mozilla browser cake wars (https://www.youtube.com/watch?v=7CObnXjmDtg https://www.youtube.com/watch?v=7CObnXjmDtg), and even today it's still not resolved (https://www.theregister.com/2018/08/28/ipv6_peering_squabbles/ https://www.theregister.com/2018/08/28/ipv6_peering_squabble...). Even Google is not spared with this interconnection woes: it's mitigated, sure, but there are still some parts of IPv6 internet that cannot reach Google, it's just those parts don't really use Google's services or have sane IPv4 interconnectivity (and to clarify, this isn't due to state-level blocking, those people just didn't realised that they don't have a path to Google via IPv6).