Blanket policy of /48 per end user comes from a (now obsolete) RFC3177. All RIRs now have less generous recommendations - both RIPE [0] and ARIN [1] seem to operate in /56 granularity nowadays, which is a very sensible step forward of course.

[0] https://www.ripe.net/publications/docs/ripe-650

[1] https://www.arin.net/policy/nrpm.html#six7