Recommended Reading
I believe that all of piano technique comes down to one goal ultimately - to optimise legato.
All fingering strategies, scale revisions, arpeggio practice and quasi-mechanical fingering exercise are devoted to enhancing the player's ability to play as legato (smoothly) as possible when need be.
The transition from one note to the next when playing piano must be as transparent as possible and the notes must be as connected as possible - this will give legato. Improving fingering & piano technique as well as strengthening the weaker (little) fingers will all help towards legato.
What may seem easy in the short-term, when reading and interpreting a piece for the first time, will later cause problems, if incorrect fingering is being used - the piece could sound 'clumpy' or slapdash.
Even optimising fingering for a piece will not optimise legato fully. To optimise legato fully it is essential to train the student in the ways of Hanon, or a similar expert of mechanical exercises for the fingers - these are suitable for all students from age of eight to eighty eight.
