have junglers forgotten how to smite right?

This is not meant to insult any of you proud junglers out there, but recently, I noticed how many games turned 180° because the jungler didn't smite baron/elder dragon at the right time. You should think the higher elo you get, the less often it happens. I'm in high plat atm, playing with diamond 5 - 3, and it's frightening how many junglers in my team, but also in the enemy team lost the game for their team by smiting wrong. I had 2 games the past games where it was especially odd. In one of these games, my jungler smited at 1.5k baron hp and made it possible for the enemy jungler to just chill before smiting, because the baron still had 700 hp. The other game, the enemy jungler smited a bit too early and my jungler got the baron. Getting baron stolen usually doesn't necessarily means losing the game, but in each of these games, the team that lost baron was leading and the baron steal turned the game around heavily. If you're a jungler and this happened to you often too, do you know why? Like are you scared of missing smite so you rather use it too early than too late? Or is it just pretty unlucky? But why does it happen so often then.. I would like to know.