You'll barely have to deal with stress in you're household because you basically run the household! You have the parents in the palm of your hands so whats to stress about? No worries about grown up stuff, thats basically already taken care of by your parents who
One of the best perks of being the youngest sibling is that your pets will ultimately love you more. Because your older siblings will move out before you, your pets will appreciate you because you didn't leave them :')
The 'baby' image you've made for yourself has its upsides and downsides. The upsides are all listed above with jealousy from other siblings, getting whatever you want, love from the parents etc. The downsides are that you'll hate family reunions when you're grandma treats you like a 4 year old who can't form a basic sentence. Its annoying at times but worth it in the end when you grow up and you are still viewed as the cute baby.
At some point it is inevitable that you're older siblings will get jealous of you're baby face and big ticket items. You got it good in life, who wouldn't want to be you? Older siblings have to worry about college and money while you just get to chill out and ride the relaxation train.
You'll almost always get what you want. No matter how stupid the object of your choice is, the parents will probably buy it for you if you give them the classic puppy dog face or just by saying 'pretty please?'. The advantage in these situations are in your court and if you're smart, you'll use this advantage for big items that you don't really need in life, but just want for fun.