Likely same reason as many, many other things: the modern 'automated' version (tie wraps usually) is easier, cheaper, faster. And has the standard consequences which unfortunately get ignored: requires close to no skill, plastic, seldom reusable, probably won't get recycled and ends up as waste eventually. Lacing has some of those disadvantages as well though.
One big problem with lacing is that it's one long string of knots instead of many individual tie points. You can always cut a zip tie and replace it with another. For lacing that was cut in the middle fixing is a slightly more involved process. So unless it's a final install it could bring some headaches. It's very unforgiving if you realize you got something wrong.
With regards to the material used, I have never used or seen waxed linen cord. It was always purely synthetic (plastics) possibly due to cost, availability, or performance.
> For lacing that was cut in the middle fixing is a slightly more involved process.
Only if you are speed lacing and do not knot the intermediate restraints. If there is any chance that you will need to break apart mid line you add a stable knot at each intermediate and can simply break between any tie.
True and this may help if you just want to detach 1m of cable from one end (perhaps to route it another way). But replacing one cable in such a bunch is either a nightmare or a serious time sink, depending on how you look at it.
Zip ties are cheaper and faster, velcro might not be cheaper but still faster and a lot more flexible. This being said if I want to send a rover to Mars (so definitely a final install) I will not use zip ties :).
Why is it a negative consequence that the replacement requires no skill? Turning on a light switch requires far less skill than trimming wicks for oil lamps, but I'd consider that a feature not a bug.
Creating a wiring loom is a skilled task. If you keep those same skilled workers and make part of the job easier that's probably a good thing.
What sometimes happens is that a PHB will see the switch away from lacing and to cable ties and think that the rest of the job is now lower skilled, and they put lower skilled workers on that job. This is bad, because wiring looms are tedious to inspect and test, and we now need better inspection and test to compensate for the lower skilled staff.
Also, because cable tying tends to be done with a hand tool (reproducable tension, uniform cuts, speed of assembly etc) there's a small risk of repetitive strain. I used to use this tool, and it was okay if I was doing the entire loom, but it sucked if I had a big pile of other people's looms and all I was doing was adding cable ties. https://uk.farnell.com/duratool/d03033/cable-tie-gun-stainle...
