Today in our newest take on "older technology is better": why NAT rules!
Having a large range has a number of benefits though. Companies that have dozens of IPv4 ranges may be fine with a single IPv6 range, which simplifies routing rules.
A lot of features in IPv6 take advantage of the fact that networks have at least a /64 range (at least if they're built correctly according to RFC4291 and newer specs). SLAAC is a major one: Devices can auto-configure IP addresses without having to use something like a stateful DHCP server.