Why's Baron only worth 25 seconds of our time?

I don't get what's up with that. You play the laning phase well, which is like 10 to 15 minutes I guess. Your team does well, so well in fact you're ahead by 4k gold at 20 minutes. Even though one dude on your team is feeding, it's okay, cause everyone else is doing alright, and his deaths are evenly spread so no one enemy is super powerful. Flash forward a minute from 20, crappy situation, 2 people get caught, team decides to play safe, back, and clear waves. Boom. Baron gone. Okay, no big, we turtle. Except they run it down mid and force fights, and win each time. So, we lost.

Another example, losing game, down by 3k gold, botlane feeding, mid top jg are doing alright. Mid and top distract, creating big minion waves to push, botlane and jg sneak baron. Successfully take Baron, boom, now big Baron buffed creeps are taking towers while the enemy slowly clear them. So obviously, enemy team can turtle, or make a pick on a rotation then force a team fight. So they turtle, there's lots of minions so they can't really afford to look for picks. We run it down mid, they try to force a teamfight but we beat them, and then we win.

I get that Baron is supposed to be a game changing buff, and it's supposed to function as like hope for the losing enemy team. But let's face it. The rewards heavily outweigh the risks, because it's really not hard to take Baron. Any two teams that are going even with each other can clear wards around Baron about 20 seconds before it spawns, put their own wards up in top jg for sneaky picks, pressure top, then take Baron within 20-30 seconds. It may just be me, but it feels overwhelmingly powerful for how underwhelming Baron is to take.