Couldn't agree more re oil analysis.
It is done simply when changing the oil. Wait about 30 secs and then divert a bit into a little bottle. Run the engine first, to make sure it is well mixed up.
I bought a large # of prepaid kits for £6.50 each a few years ago, which get mailed to the USA for analysys, and I think there are some deals around, though not quite as cheap.
Unfortunately some of the really really obvious cases of fatal accidents and knackered engines, I don't think anybody was cutting open the oil filter either, and that is a whole lot more serious. Almost nobody (except IFR tourer owners possibly) does oil analysis but cutting open the oil filter should be 100% standard.