Kosten vs. Pendelverkehr für grenzüberschreitende Luxemburger Städte

30m commute from Arlon?
Did the person who made that had a look at the peak hour traffic beforehand?

Are these commute times at night on a weekend?

It can easily take you an hour to get from one side of the city to another (especially with buses) so this mostly depends where you work. If you work in the south, obviously Thionville and Longwy can work for you. If you work in Kirchberg or the center you are f*** from whichever side you are coming but German side is at least more tolerable than having to commute from Trier to a location on the southern or western side of the city.
Arlon is the fastest train (when they’re running) but if you need to switch at the Gare and go somewhere else it will easily swell up.
Arlon is popular with people who work in Capellen or Strassen. TLDR it really depends where exactly in the city your office is.