It's a bad practice always since the user can easily choose if he/she wants to open it in new tab by themselv but not the other way. For a user there is zero benefits in this practice

"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.

Right click, open in new tab? I’m surprised if most people don’t know this

If with "most people" you mean people aged 12 to 30, possibly with some form of higher education, then I grant you your surprise.

However, most people are not very skilled when it comes to computers.

I implore you to see how most people use computers more, because no: Most people don't know how to right click.

Most people don't know tabs or multiple windows, either.

Thanks. The issue is now fixed.