Newbie question.

Newbie question.

I bought some vegetable plants a couple days ago. I know that when you're transplanting you want to get the plant in the dirt as deep as it was to start out with, but on my tomato plant there was a note on the side of the pot that said for a stronger plant later you needed to bury 80% of the little one. I pretty much did that. I'm just wondering why. Will burying more of the seedling help the plant build a stronger root system?
Me and My Zucchini….

Me and My Zucchini….

My roooommm

My roooommm

Poinsettas

Poinsettas

Bug ID and Lily ID

Bug ID and Lily ID

trying my hand at this gardening thing

trying my hand at this gardening thing

3…2…1…

3…2…1…