They make custom lengths. For example they made a 6.5 meter pair of interconnects for one of my customers and he couldn't have been happier. But they don't go much longer than that due to the manufacturing processes. The speaker cables are available up to 4 or 5 meters.
I understand and agree there is no one size fits all when it comes to cables, due to electronic characteristics, impedances, and subjective preferences.
I understand and agree there is no one size fits all when it comes to cables, due to electronic characteristics, impedances, and subjective preferences.