== Why is this an issue?

With `string.StartsWith(char)` and `string.EndsWith(char)`, only the first character of the string is compared to the provided character, whereas the `string` versions of those methods have to do checks about the current `StringComparison` and `CultureInfo`. Thus, the `char` overloads are significantly faster for default comparison scenarios.

These overloads were introduced in `.NET Core 2.0`.
