It's just for convenience. Some people will use their keyboards as much as possible and there mouses as little as possible. The backspace button helps these people.
There is the equivilent to a 'backspace' button. It is called the 'delete' button and has the same functions as windows backspace button. It is located in the top right hand corner of the keyboard
if you have a mac you hit the delete button if you have PC you hit the backspace button
On a Mac, the "Backspace" key is labeled "Delete" instead.
backspace
the backspace button
The Backspace button
Push the "Backspace" button on your keyboard. If it still does not drop, then push the Backspace button repeatedly.
Select the word and press either backspace or the left-arrow.
To drop an item on Roblox, press the backspace button. Be aware, the thing might bounce back and get in your inventory. Try backing away while dropping it.
Backspace
If you have split coke on your laptop it might make your backspace button hard to press. You might need to replace the key.
Press the backspace button.