I've heard that as well, but I'm not sure my tone is refined enough to notice the difference unless I was recording. I've often wondered the same thing about having multiple effects pedals and signal routers in the chain: surely that's got to have a big degradation effect ?
I've gotten to the point where my "multiple effects pedals and signal routers" are pretty much my right hand; my only effects are roundwound/flatwound, differing attack, palm muting, pick or fingerstyle, etc.
Bass-quality cable-tube amp-cab-microphone. As with many I've gone full circle, bass into tube amp gradually transitioning into transistors, bi-amping, effects and wireless, back to bass into tube amp.
Moserite into Fender Bassman in 1971 (couldn't
afford Sunn)
Active basses wireless into effects board into this rig in the early 90's...
Back to passive US basses and this main gig rig currently...
Still have some big guns if I'm ever feeling froggy, but I never seem to feel froggy anymore...