staehp, what speeds are your bikes? 7, 8?
I'm fairly certain I've said this before, but as a light guy who doesnt stress a chain much, and who also like you just does the rag thing regularly and lubing as well, I generally reach the 5-6000km mark at about 1/16 with 9 speed stuff, and it was probably a bit more with 7 and 8 speed.
My heavy touring bike that I did the TA and some other loaded tours with has a 9 speed cassette. That is the one that I actually did the best job of keeping track of the mileage on the chain and know that it went about 10k miles.
The bike I did the ST with carrying an ultralight load was a 7 speed, I am less sure of the mileage on that chain since it was spread over different usages over quite a few years. It served in a number of roles between 1990 and now and is currently serving as my adult daughter's commuter.
I have a couple 10 speed bikes but they have less mileage on them and I did a poor job of keeping track of their mileage, so I really don't know with any accuracy how their chains have held up, but my impression is that they seem to be doing okay.