Rift Herald is almost never taken
Its exceedingly hard to take and doesnt give a buff except to one person, which is only usable if you are going to splitpush.
But if the reward was changed to something that helped the team that got it in a more concrete way...
The team that kills Rift Herald gains the buff "Glimpse of the Void" which is active on all five players on the team that takes it until the 30 minute mark. Glimpse of the Void grants 15% increase damage to Baron and Baron deals 15% less damage to the recipient.
Suddenly Rift Herald goes from an exceedingly hard to grab, incredibly niche buff, to one where teams would more readily look to take and fight over it, as taking it would lead into furthering your mid game advantage, or allowing you to take a desperation baron if you are behind.
and
and both can solo it at level 6 (Yorick w/ ult, Aatrox w/out).