These are my Mizuno Enerzy. They are only a few years old, but they survived my 110kg to 75kg, 5km in 50 mins to 10km in 55 mins fitness journey. Its getting a bit embarrasing at the gym when people see the duct tape. Ive already stitched the holes up three times.
How long are running shoes supposed to last you? They are expensive! Are they expected to do this, or should they last much longer?
As others have said, it's usually the Midsole foam going flat that causes the issues. That usually happens long before any wear is visible. I used to do 600-800km in regular running shoes. After that, knee and hip pain set in pretty predictably.
But changing shoes twice a year is super annoying, so I've switched to barefoot shoes. Those don't have a midsole to begin with, so you can wear them until they literally fall apart. My current pair of Xero Shoes is on about 2k km or so and still going strong!