"The user" on a typical website does not know how to do this.

For a user there is the benefit that they will not lose their presence on the website. Many users do not know how to navigate back.

Of course, in times long gone a new window would appear, and the pattern made even more sense than with tabs.

If you would have left out the word "always", I might have agreed that for this particular website and intended audience, it does not make much of a difference.