Heavy flouro or mono leaders should be pre-straightened before you use them. (I use 60 - 80 lb) Not all monos and flouros are created equal, some brands are definitely harder than others and that's what you should use. For mono, it's hard to find harder than Mason hard mono,,, and for flouro, seaguar "blue label" has a harder finish than many other flouros.
I make my own, I precut the leader material into two foot lengths and slip into a 2 foot tube of 1/2" diameter threaded pvc conduit. I pour boiling hot water into the tube, seal it, and leave for a few minutes. When you pull out the leader material, it will be perfectly straight now.
I crimp the ends rather than tie them, much easier than knotting. The business end is a snap plus small swivel. I simply loop the other end that attaches to my main line. I also put a small surgeons loop in the main line and the leader is attached by a loop to loop connection, facilitating easy and quick leader changes on the water.
If you can remember to check for open snaps and leader nicks (change out leader right away if nicked) you can save a lot more lures ,,, but even at that, venus and mars and the pike's teeth can still occasionally align themselves just so,,, and you will get the odd bite off.
That said I have also seen wire fail (often at the knot / crimp),,,, and 20 - 30 lb multistrand can even be bit through when all nine planets align just so!!!
Just the same,, wire is still tougher,,, but I hate kinked leaders,,, so I prefer flouro.