MC cart rebuild frequency: a question for you

I heard an interesting -albeit a little discouraging- point of view regarding fancy MC carts installed in highly revealing systems. I am not sure what to make of it all.

The gentleman in question listens to several hours of music on vinyl records seven days a week. He says he notices his cartridges sounding tired after a few months, and that cartridges should be rebuilt/replaced every year or so irrespective of use, and after they have been cued a few thousand times the fragile assemblies need replacing or rebuild. They still work, but the difference in the sound is noticeable once you put a fresh new cart in. Notwithstanding "break-in" sound, of course.

I like to think my system is revealing and my VDH cart -purchased new- is an expensive item in my world. It still sounds good to me after two years and I am I not noticing it getting "tired" because the decline -if any!- is so progressive, kind of like getting fat with age: if we gained 20lb overnight we would freak out, but since it is gradual we hardly notice...
...until we install a new identical cart.

In other words, would one be better off having two identical $1000 carts on a rotation (one in use, the other in the process of getting rebuilt) of one rebuild per cart per year to keep all moving parts "fresh" and carts always in peak condition, or would one be better off with a $5000 cartridge getting a rebuild every 5 or 6 years, or 2000 hours, whichever comes first.

See what I mean? Is the sound of a lesser -but fresh- cart better than the greater cartridge on a less frequent rebuild/replace schedule, all other things being equal, using only freshness and newness of the suspensions, cantilever, diamond, as a criteria.

I do not have the financial means to conduct the experiment for myself. I figure since the market for used cartridge is alive and well, the difference between a "aged" low-hours cart and a fresh one have to be minimal, otherwise no one would buy them and it would be well-known.

I'd like to hear what you think, what your experiences are.
Best,
Jerome