I've also noticed that Dishwashers are less effective than they used to be.
I thought it was because I was cheaping-out and getting the most affordable one I could find. So this time, I bought a top-of-the-range Bosch. My wife hates it.
When I have a lot of dishes, like with family over, I'll run the 1/2 hour cycle and 80% of dishes come out clean, then I'll swap out 80% and run the 1/2 hour cycle again, I might leave a few in there on the long cycle when I'm done and in the time it takes to do one load, I've cleaned dishes for 12.