Baron and Dragon Extreme Snowballing

Back in season 4, dragon and baron gave gold, and gold+stats (including regen), respectively. This meant that if you lose consecutive dragons and barons, its still possible to come back if you get gold from elsewhere or don't need gold. Waveclear being equally effective at all times in the game means that defending teams that are down still can win through a teamfight where they turn around a tower dive and ace/near ace the other team. This means that the winning team still has to outplay the losing team to win. On the other hand, a losing team that manages to steal a baron turns the game around because they not only have combat stats but also have increased regen to turtle more effectively, and the longer a game goes on, the less and less that early lead matters.

Now, that is not possible, because a team that's ahead can snowball its vision advantage such that dragon and baron are never safe. Once baron is secured, it is nearly impossible to lose if you are ahead because side lanes will constitute inhib threats even if its just the support splitpushing, and the recall time means that disengages are easier. Meanwhile, because regen is removed, baron on a losing team means much less because the aura doesn't help you except to stall out enemy waveclear, and it still leaves you vulnerable to getting poked. Dragon on losing teams also means much less than on winning teams thanks to percent increase bonuses instead of flat gold.