As an electrical engineer, I firmly don’t believe most of the snake oil marketing of expensive cables. I own one guitar cable that has the plugs marked as to which end should be plugged into the bass and which into the amp. It sounds the same to me if I connect it “backwards” and no different than the other generic cables I normally use.
That said, I
have heard differences between cables, both guitar leads and speaker cables.
Someone left a Monster “Bass” 1/4” cable at a jam session one night, so I took it home and brought it back every week until it’s owner claimed it. While I had it, I A/Bed it against a bog-standard Belden/Switchcraft cable. The Monster
did sound completely different.
Actually, it sounded “hi fi” mid-scooped 
Since Monster at the time was selling cables meant for guitar, bass and keyboards I can only assume that the RLC parameters of each cable was tweaked to provide particular frequency responses in each instance. Monster also sold even more expensive cables meant for recording studios that were
not instrument specific. That only reinforced my belief that the designs were specifically tweaked to provide a certain sound.
I was unimpressed with Monster, especially at the price point, because the first few years these were on the market I heard from many users who told me their cables would fail mid-gig after a few weeks. They were unconcerned because of the lifetime warranty, stop into GC and get a new one. I have no idea if Monster's QC has gotten any better 20 years later
As far as
speaker cables, I bought some high-end stereo speakers about 20 years ago and the dealer recommended two different cables. He said while he agreed about snake oil in his experience with a particular amp/speaker combination some cables
did sound better than others…but not always the same cable! He sent me two pairs of cables and I set my receiver up to a jazz station playing in mono (so each speaker got the same signal). The lower priced cable easily beat out the zip cord I always used before. Louder, more open. Then I A/Bed that cable with the more expensive cable. They sounded similar overall but I was able to hear details of the drum stick hitting the ride cymbal with the more expensive pair that I couldn’t hear at all with the other. Considering the signal path (mike -> preamp/mixer -> recorder -> studio mixdown -> mastering/pressing -> CD player at the radio station -> radio transmitter -> my receiver -> cables -> speaker) I was amazed that such fine detail survived that path. So I kept the more expensive pair, sent back the cheaper pair and threw my zip cords into the trash.
All I can suggest is if you have a few hundred bucks to spend, buy a few different brands of cables and A/B them as best you can.