I have made mine out of Titanium, they are a bit more money but much easier to work with, smaller diameter/lb. and virtually no kinking at all. I get them locally but I am sure the wire is available on line.
More $$ - True.
Easier to work with - Not really. Knots can be tied but there's always a stiff tag end sticking out to catch weeds or, worse yet, poke your hand or finger when you're landing a fish. Bet I can make an uncoated wire connection as fast or faster than you can tie your Ti. Mine will look neater and fish cleaner too. No brag, just fact.
Smaller diameter/#test - Nope. From the vendor sites:
AFW uncoated steel wire 20# test - .011" diameter
Knot2Kinky Ti tieable wire 18# test - .012" diameter
Reality, .001" is nothing to get excited about either way so as far as I'm concerned it's a wash.
Virtually no kinking at all - Yep! You got this one. But really, I don't care 'cause steel is sooo cheap I can swap out in seconds and repurpose components.
I've used the Ti stuff and I am not fond of the single strand. I did just get a spool of 7 strand to play with but, again, it was comparatively very expensive. Almost 3x as much as steel. It's brand new to me this year so I haven't had a chance to give it a go. My only knock on Ti other than cost is that it's elastic/stretchy. Really. Take an 18" piece and hook up to each end and pull. It is really stretchy. It's really kinda fun. Problem comes when it stretched too many times and fails.And it will with zero warning. You can see if mono or fluoro get beat up. Same with steel and swap out before a failure. Ti looks great right up until it fails. And it's expensive to swap out preemptively.
In the end it falls back to $$ and ease of working. You know where I'm at.