I have 2 problems.

It's too easy to accidentally write `if err == nil` instead of `if err != nil`. I have even seen LLMs erroneously generate the first instead of the latter. And since it's such a tiny difference and the code is riddled with `if err != nil`, it's hard to catch at review time.

Second, you're not forced by the language to do anything with the error at all. There are cases where `err` is used in a function that not handling the `err` return value from a specific function silently compiles. E.g.

    x, err := strconv.Atoi(s1)
     if err != nil {
      panic(err)
     }
     y, err := strconv.Atoi(s2)

    fmt.Println(x, y)

I think accidentally allowing such bugs, and making them hard to spot, is a serious design flaw in the language.