12 years with the same AIO without any replacements? That's definitely an excellent case scenario. I think I read from a poster here who's on their third radiator for the same system within 8 years.
Anecdotal evidence, probably from smokers with pets who place their systems on carpeted floors. 😅
10 years with one, 2 years with the other. First one was the Corsair H50, 2nd one is the H115i Platinum. The Corsair H50 is still going on my Dad's system though. My systems always run 24/7, his does too. Basically that wee H50 has worked its socks off for years.
Like anything, you need to be careful what you purchase and go with tried and tested models/brands etc. I doubt it would be a modern day Corsair unit to go through 3 radiators. If it is.... what on earth are they doing to the radiator? It's a radiator, it's basically a tank for water. Shouldn't ever need replaced no matter what happens.
There's anecdotal evidence that can be relied upon, and made up anecdotal evidence to try and prop up a point. I've witnessed an awful lot of hearsay with AIOs over the years. The proof is in the pudding on here IMO as I don't think I've seen an issue with a build I have recommended yet. As a matter of fact, the only AIO issue I can even think of was with a PCS Frostflow model..... which I wouldn't recommend due to unknowns.