I'm curious about something so I'm going to throw this thought experiment out here. For some background I run a pure IPv6 network and dove into v6 ignoring any v4 baggage so this is more of a devils advocate question than anything I genuinely believe.

Onto the question, why should I run a /64 subnet and waste all those addresses as opposed to running a /96 or even a /112?

1. It breaks SLAAC and Android

let's assume I don't care for whatever reason and I'm content with DHCP, maybe android actually supports DHCP in this alternate universe

2. It breaks RFC3306 aka Unicast-prefix-based multicast groups

No applications I care about are impacted by this breakage

3. It violates the purity of the spec

I don't care

What advantages does running a /64 provide over smaller subnets? Especially subnets like a /96 where address count still far exceeds usage so filling subnets remains impossible.