An eye splice is a definite skill to learn. and satisfying to do as well.
I've never had he need to use a long /short splice although learnt many years ago , so have probably forgotten how to do them.
I've also never learnt how to splice braided line - it that useful ?
The other useful skill is in whipping -lashing to prevent a line from unravelling - not the 50 shades type (although some might find that a useful skill too
). From what I see, whipping has been replaced by just heat sealing the end of a line, but I always throw a whipping on as well as extra security