If you see the enemy doing baron/drake, you don't need to group up and try to steal it every time.
If it's theirs, it's theirs. You might be lucky stealing a baron/drake, yeah sure, do it with MF or Lux, but if you happen to get your whole team killed for trying to steal a baron, you will just cost the game. Sometimes it's just better to give the objective to the enemy team if it means keeping most teammates alive. I see many people with this mistake, and I'll admit, I did it too, but after matches of realizing it's not worth, I just tried to defend while enemy team is doing the objective. Just a tip for the future.