Just my $0.02 cents worth....
Most of us can fillet fish, flesh and skin our game with the same skills it takes to sharpen our knives.
It is a blessing in my life to share those skills with local youth, and it would surprise you how fast they catch on!
It's not a forgotten art to sharpen a blade 'free-hand', we may be giving up a lot of practical field skills when we do use training-wheels, we may becoming reliant on them?
Just to add a couple points I believe in, it seems just as easy to test our sharpening skills as it it to know when a blade has lost it's edge.
We all may have a different ideas and need a different approach to learning the free-hand method, may I share a picture of one of the kids that has it mastered?
I guess my $0.02 cents worth would be that the advantages of mastering free-hand sharpening are well worth the time it takes to learn them.