There are too many IPv6 addresses for hoarding them to be a problem any time in the next few hundred thousand years, at least with the current deployment strate

There are too many IPv6 addresses for hoarding them to be a problem any time in the next few hundred thousand years, at least with the current deployment strategies. Currently it's recommended for ISPs to hand out a /32 to every ISP that requests one, and a /48 to every ISP customer (though residential ISPs will often only hand out /64s). But only the 2000::/3 IPv6 space is available, the remaining 7/8ths is reserved in case that allocation strategy is too liberal.