It’s seems you have not heard Audio Envy cables. If you did, you have not made the above statement. The bottom line is most top cable designs utilize OCC as it gives the absolute purest base platform to get that much closer to true absolute transparency.
I have done a direct comparison between stranded OCC and low grade solid core. Comparing an extremely high end expensive 14awg Furutech OCC stranded cable used as a power cord. This comparison was with some lower grade copper, but used a multiple 20awg solid-core braided configuration. I could hear that the OCC Furutech gave better resolution, but it had a weird phasing effect and the sound was not nearly as solid or natural as the low grade solid-core. I would pick the low grade solid core every day because it was much more pleasing to listen to and give a much more realistic result.
This was just on a power cord comparison, using the exact same plug connectors, so it was truly apples-to-apples comparison. I suspect this same result would be similar when comparing speaker cable.