I dislike closed loop watercooling for a number of reasons. Primarily, I find them to be unreliable in the long term, and considering that OP seems to keep computers for a longer period of time, I suspect the likely point of failure in this next machine would be a closed loop cooler.
Additionally, it’s important to note that almost all closed loop watercooling solutions are more expensive than air.
The idea that a AIO watercooler is more capable of cooling your PC has been thoroughly debunked by multiple sources for a few months now.
Now custom loop, that’s another story.
Simply put, air cooling is more reliable, and if noise is an issue, we can look to the Greg KH build to see how air cooling can be done with noise in mind.