Unlike cars, modern appliances, in general, are not as reliable as they once were.  But like cars, the problem usually involves the system board (i.e., the computer).  I don't think those are hard to replace, but I wonder what device is needed to test one, and if buying that device would be cost effective for a homeowner.  Each manufacturer probably has its own for each appliance.

The worst appliance I ever had was an LG washer.  When the time came where I spent as-much money on repairs as the original price, I got rid of it.