Because otherwise we don't need ipv6. Google advertised the use of ipv6 heavily. If everything still works fine with ipv4 and NATs, why should we ever switch? I

Because otherwise we don't need ipv6. Google advertised the use of ipv6 heavily. If everything still works fine with ipv4 and NATs, why should we ever switch? It's a serious question, I know that the ipv4 space is somehow exhausted, but I can still get very cheap ip addresses (one is included in every $5 vps at major providers). If even Google with its huge network of crawlers doesn't see the need to communicate via ipv6, why should there be any demand?