Is there a glass ceiling for cable technology??

As long as cable manufactures employ marketing and PR firms, there always will be advancements.

Any cable will have a different on your equipment, so anything they put out can sound different than the cable they produced before no matter the brand. Never was a ceiling just impendence effects between 2 pieces of gear and then the wire connecting them. This why you have to try before you buy, it a crap shoot on the sound out come. Yes every year a new name to keep the product fresh and us buying them, now a new cable weekly comes out, a very money making business as a side line for many.

"There's a well-heeled sucker born every minute."
Many of these suckers are "audiophiles."