Has biwire speaker cabling become "old" ?

I'll biwire if my cables are setup for it but can't claim I hear any difference.
Just remember if you use a jumper at the speaker terminals and measure resistance with an ohm meter you find a short. If you remove the jumpers and run biwire cable from a single set of binding posts at the amp end, you will still measure a short at the speaker terminals. Electrically the two points are identical either with jumpers or with biwire cables. It makes me wonder what sonic difference the extra wire could make.

IMO some speakers do benefit from bi wiring and some to a lesser degree. I've been trying to find a 1 meter pair of top of the line bi-wire cables for my tube mono-block amps. They are just too hard to find in a 1 meter length terminated. I'm puzzled on that front. I simply don't like my system with the jumpers in place. I've tried inexpensive to expensive jumpers and my system seems to have a restrictive soundstage vs bi wiring my system with the same type wire. Even when I try different wiring on the woofer and the 40" Ribbon I get different sound characteristics. My speakers are Apogee Centaur Majors and my Mono-blocks are Lang M70 push pull parallel amps with a Dynaco Lineage but with 4 EL34's and a 6SL7 and 6SN7 octal front end.

I have bi-wired every speaker that I've owned that could be bi-wired, but never heard any difference in sound. Bi- amplifying is the only way I heard a difference. Just try it both ways and see (hear) what you like best.

For short distances within home audio applications and audio-signal it doesn't matter. I used single wire-run threaded through both upper and lower binding posts instead of jumper, now I have bulk Kimber 4tc where 3x3 wires are hooked up to bottom binding posts and 2x2 wires hooked up at upper binding posts and it doesn't matter simply due to very small degree of magnitude to be somehow noticable.
Not sure if I hear any difference between types of connection when length of speaker wire is increased by 10x per each speaker.

In terms of the initial question, I have not noticed that there are less biwire speakers, but that cable companies are offering less internally biwired cables in favor of double runs or jumpers, though many cables are easy to reterminate to be internally biwired. so maybe internally biwired cables are currently out of favor...