Do we still need to use `[...]` in Bash?

If don't care about compatibility or portable issue, do we still need to use test construction [...] in Bash?

Many tutorials/books tell that [[...]] is more better and more flexible than [...] e.g. [[...]] is support glob/regex, But today I still see many people prefer to use [...] as standard form.

What is a reason behind this? What [...] can do but [[...]] can not do?