Used to think KB were great. Now that I delve much deeper into the exercise physiology world, I am just at a point where I can't see the purpose of KBs vs any other lifting tool like a barbell, dumb bells etc. I mean, I sometimes use a KB like a DB due to it being easier to carry for a weight vs a DB, but honestly, in hypertrophy or strength, I can't seem to find the point. Remembering that specificity is one of the biggest requirements in a good training program, a lot of things that KBs are used for seem to be more focused on conditioning yet pushed as if that same movement is great for hypertrophy or strength, when there are much better options available that would be a better use of my time. Take KB swings. They aren't a very good stimulus for growing the hamstrings vs good, deep RDL/SLDL, seated or lying leg curls etc. Those are absolutely proven to grow hamstrings. KB swings haven't been shown to be as effective and if the idea is conditioning, seems to be a way to needlessly create too much fatigue for the benefits the movement gives the individual. Single arm KB upside down shoulder presses are another I used to do for shoulder stability. But, I honestly had never done proper barbell overhead presses. Once I actually did do those, any reason id have needed to do stability exercises on my perfectly fine shoulders became obsolete. I even have partially torn my rotator, but again, the good ole fashioned OHP was fine. Heck, given hypertrophy is my current focus, simple side laterals and upright barbell rows are what I fucus on, b/c one honestly gets plenty of front delt work doing chest pressing and dips, and the best way to make your should cap and look huge is side delt work. I still occasionally do OHP with barbells in certain mesocycles b/c I just love doing them.
I just feel like a lot of KB training falls into the "looks very cool" category, take Turkish Get Ups (man they look cool, but fail to really do anything to help your mobility or train your core-I've finally come around to this reality) for example, yet for many outside of specific sports focused training, are useless and a waste of time given all of the other movements available to the trainee to do.
Hey, in the end, if you love KBs and they give you a reason to be motivated to train, do them! But just realize they are probably best used for very specific athlete needed purposes and not necessarily for the training public in general focused on hypertrophy or strength. MAybe I am wrong though. I am open to debate always with this stuff.