Having the ability for Date ranges for groups would be very useful.
Bands do disband and reform all the time, sometimes with many years between disbanding and reformation.
example: Deep Purple first active 1968-1976 when they disbanded, then they reformed in 1984 and are active to this day (https://en.wikipedia.org/wiki/Deep_Purple )

This can also possible be useful for labels: https://beta.musicbrainz.org/label/71247f6b-fd24-4a56-89a2-23512f006f0c https://beta.musicbrainz.org/label/2276f06e-f65a-4d61-9dee-9f95ff4b775c
and possibly places too.

But should (probably) be disabled for artist(person)