Consider these 3 things:
1) It is easier to press the strings down more intently if you have some kind of “point” to your approach, as if you were pointing to the string you wanted to push.
2) The hardest part of your finger is the tip, where the bone is closest beneath the skin is on the tip of your finger. Using this surface you won’t need to press as hard as you would if you were trying to make firm contact with the “fleshy” part of your finger.
3) When playing chords it is easier to place your fingers between the strings if you are using the tips. In fact its not possible to squeeze them in between two strings if you don’t sometimes.