You assume new entrants or smaller entities would have a fighting chance in this scenario. They would not. The incumbents would become king makers. They would

You assume new entrants or smaller entities would have a fighting chance in this scenario. They would not. The incumbents would become king makers. They would decide which services would be allowed on the IPv4 Internet, which would be the only Internet, and which services would be allowed to prosper. The incumbents would either acquire all successful startups and smaller companies or clone their services. New entrants would wither on the wine on this obscure IPv6-only network that hardly anybody knows about or is able to access. This would also kill off IPv6 completely. The incumbents would have a collective interest in maintaining and propping up their position. IPv6 would be a threat to this, so it would be given the axe. This isn’t some far out fantasy either. This is how mobile phone services worked during the SMS era before the Internet was a thing.