That sounds like a lot more active life than an average consumer. It would be nice if USB C could handle that kind of duty, but for most people, the 1/8 and RCA, or at least the cheap versions, might die of fatigue before the USB C has an issue. I remember non-pro audio cables as being insanely unreliable, like, you could break them in a week of light use.
USB C doesn't have that issue. There are high end cables and just kind of OK cables, but at least with the braided ones I normally buy, there aren't many terrible ones at any price. They decoupled reliability from craftsmanship and materials.
Pockets should be considered industrial duty environments.
Right next to a person is a much harsher environment than people think it is, stuff people carry tends to break and wear.
I'm not surprised the cables break in pockets in that kind of scenario, although I haven't experienced it myself with my admittedly much lighter and less varied lifestyle (lots of walking, occasional hiking, maintenance work sometimes including light carpentry, but no sports or biking).
There seems to be a very large variance in percieved reliability of cables and tech in general. Are you buying the same brand every time you need to replace something? Do more athletic people with more muscle have problems because their weight or level of force they commonly apply is more likely to break stuff? Probably just unrelated factors but it does seem like people who lift are more like to hate new tech. Is it about what clothes you wear? Is it the phone itself having something about the connector?
Obviously USB C has a problemwith a few specific environments, but I'm not exactly sure what those cases are.